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                                                                Exhibit 10(k)(i)



                                                                 EXECUTION COPY


                    AMENDED AND RESTATED EMPLOYMENT AGREEMENT


         This Amended and Restated Employment Agreement, dated as of the 27th
day of September, 2000 (this "Agreement"), is entered into by and between NAHC,
Inc, a Delaware corporation (the "Company"), and David R. Burt (the
"Executive").

                              W I T N E S S E T H:

         WHEREAS, the Company wishes to employ the Executive as Chief Executive
Officer on the terms and conditions outlined herein;

         WHEREAS, the Executive is willing to serve in such capacity on the
terms and conditions outlined herein; and

         WHEREAS, this Agreement amends and restates in its entirety that
certain employment agreement dated as of the 5th day of May, 2000 by and between
the Company and the Executive (the "Original Employment Agreement").

         NOW, THEREFORE, in consideration of the premises and the mutual
agreements hereinafter set forth, the parties hereto hereby agree as follows:

         1. EMPLOYMENT, TERM, EXTENSIONS.

         1.1. EMPLOYMENT. The Company agrees to employ the Executive, and the
Executive agrees to serve in the employ of the Company, for the term set forth
in Sections 1.2 and 1.3, in the positions and with the responsibilities, duties
and authority set forth in Section 2 and on the other terms and conditions set
forth in this Agreement.

         1.2. TERM. The term of the Executive's employment under this Agreement
shall commence on May 5, 2000 (the "Employment Date") and shall terminate on
May 5, 2005, unless sooner terminated in accordance with this Agreement.

         1.3. EXTENSIONS. This Agreement shall automatically be renewed for a
period of one year beginning as of May 5, 2005, and May 5 of each subsequent
year (each an "Automatic Renewal Date") unless either party shall have given
written notice of non-extension 90 days prior to such Automatic Renewal Date.

         2. POSITION, DUTIES. The Executive shall serve in the position of Chief
Executive Officer of the Company. As Chief Executive Officer, the Executive
shall have supervision and control over, and responsibility for, the management
and operational functions of the Company, and shall have such other powers and
duties as may from time to time be prescribed by the Board of Directors (the
"Board"), so long as such powers and duties are reasonable and customary for the
Chief Executive Officer of an enterprise comparable to the Company. The
Executive shall perform, faithfully and diligently, such duties as Chief
Executive




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Officer. As Chief Executive Officer, the Executive shall report to the
Board of Directors. The Company acknowledges that the Executive is currently the
President, Chief Executive Officer and a director of Ergo Science Corporation.
The amount of time Executive shall devote to his duties and responsibilities
hereunder will vary from week to week. On a monthly basis, however, the
Executive shall devote at least fifty percent (50%) of his business time and
attention to the performance of his duties and responsibilities hereunder. The
Company acknowledges that the Executive may conduct some of his business
activities on behalf of the Company from his offices in the Boston area.

         3. COMPENSATION: SALARY, NOTE AND BONUSES.

         3.1. SALARY. During the term of the Executive's employment, in
consideration of the performance by the Executive of the services set forth in
Section 2 and his observance of the other covenants set forth herein, the
Company shall pay to the Executive, and the Executive shall accept, a base
salary at least equal to $250,000 per annum, payable in accordance with the
standard payroll practices of the Company (the "Base Salary"). During the term
of the Executive's employment, the Base Salary shall be reviewed at least
annually by the Compensation Committee of the Board (the "Compensation
Committee") and shall be increased at any time and from time to time as the
Compensation Committee shall consider appropriate in accordance with the
compensation practices and guidelines of the Company for its executive officers.
In addition, on or prior to March 31 of each year, whether or not the
Executive's employment has been terminated for any reason on or after January 1
but prior to the date of such payment, the Executive shall receive a bonus, the
amount of which shall be determined by the Board in its discretion based on the
Executive's performance in his duties during the previous calendar year (the
"Performance Bonus"); provided, however that in each year the Performance Bonus
shall not be less than $20,000.

         3.2. NOTE.

         (a) In consideration of the Executive's efforts in settling during the
month of July 2000 the disputes related to the sale of certain assets of the
Company to Hanger Orthopedic Group, Inc., Chance Murphy, Inc. and Select Medical
Corporation (collectively, the "Asset Sale Disputes"), concurrently with the
execution of this Agreement the Company shall issue to the Executive a 10%
convertible subordinated promissory note (the "Note") substantially in the form
attached hereto as Exhibit A, in the principal amount of $60,000.

         (b) With the consent of the Company, which consent shall not be
unreasonably withheld, the Executive shall select an investment bank, accounting
firm or other entity which shall provide the Executive and the Company with a
written appraisal as to the fair market value of the Note on the date of
issuance, determined without regard to the Repurchase Right (as defined in the
Note) (the "Appraisal"). The Company shall pay all reasonable costs associated
with the Appraisal.

         (c) The Executive shall make an election under Section 83(b) of the
Code to include the value of the Note, based upon the Appraisal, in his gross
income for federal income tax purposes in the year of the Note's issuance.



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         3.3. GROSS-UP BONUS.

         (a) Also in consideration of the Executive's efforts in obtaining
settlement of the Asset Sale Disputes, the Company shall pay to Executive,
within ten (10) days after the Appraisal, an amount (the "Gross-Up Bonus") such
that after the payment by Executive of all federal, state or local income taxes
(including any interest or penalties imposed with respect thereto) imposed upon
the receipt of the Gross-Up Bonus, the Executive retains an amount of the
Gross-Up Bonus equal to the federal, state and local income taxes imposed on the
receipt of the Note. The Gross-Up Bonus shall be paid whether or not the
Executive's employment has been terminated for any reason prior to the elapse of
(ten) 10 days following the Appraisal. For purposes of determining the amount of
the Gross-Up Bonus, the Executive shall be deemed to pay federal income taxes at
the highest marginal rates of federal income taxation applicable to individuals
in the calendar year in which the Gross-Up Bonus is to be made and state and
local income taxes at the highest marginal rates of taxation applicable to
individuals as are in effect in the state and locality of the Executive's
residence in the calendar year in which the Gross-Up Bonus is to be made, net of
the maximum reduction of federal income taxes that can be obtained from
deduction of such state and local taxes, taking into account any limitations
applicable to individuals subject to federal income tax at the highest marginal
rates. If it is subsequently established (as provided in paragraph (c) below)
that the federal, state and local income taxes payable by the Executive with
respect to the receipt of the Note and the original Gross-Up Bonus exceeds the
original Gross-Up Bonus, the Company shall make an additional Gross-Up Bonus to
the Executive in respect of such excess at the time set forth in paragraph (c)
below.

         (b) The Executive shall notify the Company in writing of any claim by
the Internal Revenue Service that, if successful, would require the payment by
the Company of an additional Gross-Up Bonus. Such notification shall be given as
soon as practicable but no later than ten business days after the Executive is
informed in writing of such claim and shall apprise the Company of the nature of
such claim and the date on which such claim is requested to be paid. The failure
of the Executive to give such notice shall not relieve the Company of its
obligations under this Agreement except to the extent the Company is actually
materially prejudiced by such failure to give such notice. The Executive shall
not pay such claim prior to the expiration of the thirty (30) calendar day
period following the date on which it gives such notice to the Company (or such
shorter period ending on the date that any payment of taxes with respect to such
claim is due). If the Company notifies the Executive in writing prior to the
expiration of such period that it desires to contest such claim, the Executive
shall:

                  (i) give the Company any information reasonably requested by
         the Company relating to such claim,

                  (ii) take such action in connection with contesting such claim
         as the Company shall reasonably request in writing from time to time,
         including, without limitation, accepting legal representation with
         respect to such claim by an attorney reasonably selected by the
         Company,

                  (iii) cooperate with the Company in good faith in order to
         effectively contest such claim, and




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                  (iv) permit the Company to participate in any proceedings
         relating to such claim;

provided, however, that the Company shall bear and pay directly all costs and
expenses (including legal and accounting fees and additional interest and
penalties) incurred in connection with such contest and shall indemnify and hold
the Executive harmless, on an after-tax basis, for any income tax (including
interest and penalties with respect thereto) imposed as a result of such
representation and payment of costs and expenses. Without limitation on the
foregoing provisions of this section, the Company shall control all proceedings
taken in connection with such contest and, at its sole option, may pursue or
forgo any and all administrative appeals, proceedings, hearings and conferences
with the taxing authority in respect of such claim and may, at its sole option,
either direct the Executive to pay the tax claimed and sue for a refund or
contest the claim in any permissible manner, and the Executive agrees to
prosecute such contest to a determination before any administrative tribunal, in
a court of initial jurisdiction and in one or more appellate courts, as the
Company shall determine; provided, however, that if the Company directs the
Executive to pay such claim and sue for a refund, the Company shall advance the
amount of such payment to the Executive, on an interest-free basis, and shall
indemnify and hold the Executive harmless, on an after-tax basis, from any
income tax (including interest or penalties with respect thereto) imposed with
respect to such advance or with respect to any imputed income with respect to
such advance; and further provided that any extension of the statute of
limitations relating to payment of taxes for the taxable year of the Executive
with respect to which such contested amount is claimed to be due is limited
solely to such contested amount. Furthermore, the Company's control of the
contest shall be limited to issues with respect to which a Gross-Up Bonus would
be payable hereunder and the Executive shall be entitled to settle or contest,
as the case may be, any other issue raised by the Internal Revenue Service or
any other taxing authority.

         (c) If any such claim referred to in paragraph (b) is made by the
Internal Revenue Service and the Company does not request the Executive to
contest the claim within the 30 calendar day period following notice of the
claim, the Company shall pay to the Executive the amount of any Gross-Up Bonus
owed to the Executive, but not previously paid, immediately upon the expiration
of such thirty (30) calendar day period. If any such claim is made by the
Internal Revenue Service and the Company requests the Executive to contest such
claim, but does not advance the amount of such claim to the Executive for
purposes of such contest, the Company shall pay to the Executive the amount of
any Gross-Up Bonus owed to the Executive, but not previously paid, within 5
business days of a Final Determination of the liability of the Executive for
such income tax. For purposes of this Agreement, a "Final Determination" shall
be deemed to occur with respect to a claim when (i) there is a decision,
judgment, decree or other order by any court of competent jurisdiction, which
decision, judgment, decree or other order has become final, i.e., all allowable
appeals pursuant to this section have been exhausted by either party to the
action, (ii) there is a closing agreement made under Section 7121 of the Code,
or (iii) the time for instituting a claim for refund has expired, or if a claim
was filed, the time for instituting suit with respect thereto has expired.

         3.4. RECEIVABLES BONUS. The Executive also shall be entitled to receive
from the Company an amount in cash equaling ten percent (10%) of collections on
each receivable of the Company (each, a "Receivables Bonus") in excess of the
amount at which such receivable is



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booked on the balance sheet contained in the Annual Report on Form 10-K for the
fiscal year ended June 30, 2000 (the "Booked Amount"); provided, however, that
(i) no Receivables Bonus shall apply with respect to (a) the "prudent buyer"
receivables listed on Schedule 3.4(a) hereof or (b) receivables listed on
Schedule 3.4(b) hereof that are the subject of similar arrangements between the
Company and certain of its Employees, (ii) to the extent not already reflected
in the Booked Amount, the Company's costs from and after the date hereof
associated with collecting on any receivable shall be deducted in determining
the amount of collection with respect to a receivable, and (iii) the aggregate
amount receivable by the Executive in the form of Receivables Bonuses shall not
exceed $500,000. Receivables Bonuses shall be paid within ten (10) days after
collection by the Company on the related receivable and shall be payable
following the Executive's termination of employment, unless such termination is
pursuant to Sections 6.3 or 6.5, in which case only Receivables Bonuses for
collections prior to such termination shall be payable.

         3.5. LITIGATION BONUS. The Executive also shall be entitled to receive
from the Company an amount in cash equaling 10% of the amount determined by
subtracting (i) the aggregate of the amounts to be paid following settlement or
final judgment on each of the legal actions against the Company listed on
Schedule 3.5 hereto (the "Legal Actions"), including the Company's costs from
and after the date hereof associated with reaching settlement or final judgment
on such Legal Actions., from (ii) the aggregate settlement values given for such
Legal Actions on the books of the Company as of the date hereof (the "Litigation
Bonus" and together with the Performance Bonus, the Gross-Up Bonus and the
Receivable Bonus, the "Bonuses"). The Litigation Bonus shall be paid, if at all,
within ten (10) days after settlement or final judgment of all Litigation and
shall be payable following the Executive's termination of employment, unless
such termination is pursuant to Section 6.3 or 6.5, in which case the Executive
shall receive no Litigation Bonus.

         4. EXPENSE REIMBURSEMENT. The Company shall reimburse the Executive for
all reasonable costs and expenses incurred by him in connection with the
performance of his duties hereunder, upon the presentation of proper accounts
therefore in accordance with the Company's policies. In particular, the Company
acknowledges that Executive's primary residence is in the Boston, Massachusetts
area, and Company agrees to reimburse Executive for all reasonable costs and
expenses incurred by Executive in traveling to and from the Boston area to the
Company's offices.

         5. BENEFITS. During the Executive's employment, and thereafter to the
extent provided in Section 6, the Executive shall be entitled to participate in
all employee benefit plans and programs which may be made available to the
Company's senior executives or to its employees generally, as such plans or
programs may be in effect from time to time, including, without limitation, any
hospitalization insurance, surgical insurance, and major medical insurance for
Executive, his spouse, and any dependent, profit sharing plans, savings and
similar plans, group life insurance, accidental death and dismemberment
insurance, travel accident insurance, short-term and long-term disability
insurance, sick leave (including salary continuation arrangements), holidays,
and any other employee benefit plans or programs that may be sponsored by the
Company from time to time, including any plans that supplement the above-listed
types of plans, whether funded or unfunded (the "Benefit Plans"). The Company
shall also provide the Executive with two weeks of paid vacation each year. Any
unused vacation





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days, and any other accrued paid time off as of December 31 of each year, shall
be carried over from year to year to the extent unused without limitation.

         6. TERMINATION OF EMPLOYMENT.

         6.1. DEATH. In the event of the death of the Executive, the Company
shall (i) pay to the Beneficiary (a) within ten (10) business days after the
Executive's death, the Base Salary (at the annual rate then in effect) accrued
to the date of the Executive's death and not theretofore paid to the Executive
and (b) any Bonuses which are then or shall thereafter become payable pursuant
to Section 3.

         6.2. DISABILITY. If the Executive shall become incapacitated by reason
of sickness, accident or other physical or mental disability and shall be unable
to perform his normal duties hereunder for a period of six (6) consecutive
months, then, at any time following the conclusion of such six (6) month period,
the employment of the Executive hereunder may be terminated by the Company or
the Executive, upon thirty (30) days' notice to the other. In the event of such
termination, the Company shall (a) within ten (10) business days after such
termination, pay to the Executive the Base Salary (at the annual rate then in
effect) accrued to the date of such termination and not theretofore paid and (b)
pay to the Executive any Bonuses which are then or shall thereafter become
payable under Section 3.

         6.3. DUE CAUSE. The employment of the Executive hereunder may be
terminated by the Company at any time for Due Cause (as hereinafter defined). In
the event of such termination, the Company shall pay to the Executive within ten
(10) business days after the date of such termination the Base Salary (at the
annual rate then in effect) accrued to the date of such termination and not
theretofore paid to the Executive. The Company shall also pay to the Executive
any Bonus which is then or shall thereafter become payable to the Executive
under Section 3. For purposes hereof, "Due Cause" shall mean (i) willful, gross
neglect or willful, gross misconduct in the Executive's discharge of his duties
and responsibilities under this Agreement, or (ii) the Executive's conviction of
a felony; provided, however, that the Executive shall be given written notice by
a majority of the Board of Directors of the Company that it intends to terminate
the Executive's employment for Due Cause, which written notice shall specify the
act or acts upon which the majority of the Board of Directors of the Company
intends so to terminate the Executive's employment, and the Executive shall then
be given the opportunity, within fifteen (15) days of his receipt of such
notice, to have a meeting with the Board of Directors of the Company to discuss
such act or acts. If the basis of such written notice is other than an act or
acts described in clause (ii), the Executive shall be given seven (7) days after
such meeting within which to cease or correct the performance (or
nonperformance) giving rise to such written notice and, upon failure of the
Executive within such seven (7) days to cease or correct such performance (or
nonperformance), the Executive's employment by the Company shall automatically
be deemed terminated hereunder for Due Cause.

         6.4. TERMINATION BY THE COMPANY WITHOUT CAUSE. The Company may
terminate the Executive's employment at any time for whatever reason it deems
appropriate or without reason; provided, however, that in the event that such
termination is not pursuant to Section 6.1 (Death), 6.2 (Disability), 6.3 (Due
Cause), 6.5 (Voluntary Termination), 6.6 (Constructive Termination) or 6.7
(Termination Following a Change in Control), such



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termination shall be considered a Termination Without Cause and, in such case,
the Company shall pay to the Executive within ten (10) business days of the date
of Termination Without Cause: (i) the Base Salary (at the annual rate then in
effect) accrued to the date of termination and not theretofore paid to the
Executive; and (ii) severance pay, in the form of a lump sum equal to one (1)
year of Executive's Base Salary (at the annual rate then in effect).

         In addition, the Company shall pay to the Executive any Bonuses which
are then or shall thereafter become payable pursuant to Section 3.

         6.5. VOLUNTARY TERMINATION. The Executive, for any reason, may
terminate his employment with the Company at any time upon sixty (60) days'
prior written notice to the Company. In the event of such termination (unless
such termination is within one year following a Change in Control of the
Company, in which case the provisions of Section 6.7 hereof shall be
applicable), the Company shall pay to the Executive within ten (10) days after
the date of such termination the Base Salary (at the annual rate then in effect)
accrued to the date of such termination and not theretofore paid to the
Executive. The Company shall also pay to the Executive any Bonuses which are
then or shall thereafter become payable pursuant to Section 3.

         6.6. CONSTRUCTIVE TERMINATION. Anything herein to the contrary
notwithstanding, if the Company:

                  (A) demotes the Executive to a position lesser than Chief
         Executive Officer;

                  (B) causes a material change in the nature or scope of the
         authorities, powers, functions, duties, or responsibilities of the
         Executive as described in Section 2;

                  (C) decreases the Executive's base salary or eliminates health
         insurance coverage for the Executive;

                  (D) by vote of its Board of Directors or shareholders
         determines to liquidate the Company and 90 days from such determination
         has elapsed; or

                  (E) without limiting the generality or effect of the
         foregoing, materially breaches an obligation or covenant of this
         Agreement, the Note or the Indemnification Agreement between the
         Company and the Executive dated May 5, 2000 (the "Indemnification
         Agreement")

then, within thirty (30) days after receiving written notice of such action (or
inaction) or within thirty (30) days of learning of such action (or inaction),
whichever is later, the Executive may advise the Company in writing that the
action (or inaction) constitutes a termination of his employment by the Company
(other than for Due Cause), in which event the Company shall have thirty (30)
days (the "Correction Period") in which to correct such action (or inaction). If
the Company does not correct such action (or inaction) during the Correction
Period, such action (or inaction) shall constitute a termination of the
Executive's employment by the Company pursuant to Section 6.4 (Without Cause)
effective on the first business day following the end of the Correction Period.





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         6.7. TERMINATION OF EMPLOYMENT FOLLOWING A CHANGE IN CONTROL. Anything
herein to the contrary notwithstanding, the Executive may terminate his
employment with the Company during the one (1) year period following a Change in
Control, and such termination shall constitute a termination of the Executive's
employment by the Company pursuant to Section 6.4 (Without Cause). For purposes
of this Agreement, a Change in Control of the Company shall be deemed to have
occurred if:

                  (A) a "person" (meaning an individual, a partnership, or other
         group or association as defined in Sections 13(d) and 14(d) of the
         Securities Exchange Act of 1934, as amended (the "`34 Act")), other
         than the Executive, either (i) acquires beneficial ownership of thirty
         percent (30%) or more of the combined voting power of the outstanding
         securities of the Company having a right to vote in elections of
         directors and such acquisition shall not have been approved within
         sixty (60) days following such acquisition by a majority of the
         Continuing Directors (as hereinafter defined) then in office or (ii)
         acquires beneficial ownership of fifty percent (50%) or more of the
         combined voting power of the outstanding securities of the Company
         having a right to vote in elections of directors; or

                  (B) Continuing Directors shall for any reason cease to
         constitute a majority of the Board of Directors of the Company; or

                  (C) all or substantially all of the business and/or assets of
         the Company are disposed of by the Company to a party or parties other
         than a subsidiary or other affiliate of the Company (other than
         factoring the Company's current receivables or escrows due), in which
         the Company owns less than a majority of the stock entitled to vote for
         the election of directors, pursuant to a partial or complete
         liquidation of the Company, sale of assets (including stock of a
         subsidiary of the Company) or otherwise.

         For purposes of this Agreement (a) "Continuing Director" shall mean a
member of the Board of Directors of the Company who either was a member of the
Board of Directors on the Employment Date or who subsequently became a Director
and whose election, or nomination for election, was approved by a vote of at
least two-thirds of the Continuing Directors then in office, and (b) "beneficial
ownership" shall be determined pursuant to Rule 13d-3 of the `34 Act.

         6.8. ACCELERATION OF PAYMENTS. In the event that the Company shall fail
to pay to the Executive any amount payable pursuant to this Section 6 at the
time such payment is due (after written notice and thirty (30) business days
period to cure), all amounts to be paid to the Executive (or his estate or legal
representative) pursuant to this Section 6, Section 3 and any other provision of
this Agreement, shall become immediately due and payable without any further
action by the Executive (or his estate or legal representative).

         6.9. NO MITIGATION. In the event the Executive's employment is
terminated for any reason whatever, the Executive shall be under no obligation
to seek other employment and



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shall be under no obligation to offset any amounts earned from such other
employment (whether as an employee, a consultant or otherwise) against any
payments received hereunder.

         6.10. BENEFIT PLANS. In the event that the Executive's employment is
terminated for any reason whatever, all rights and benefits of the Executive and
his transferee, as applicable, under the Benefit Plans, shall be determined in
accordance therewith.

         6.11. EXPENSES. In the event the Executive's employment is terminated
for any reason whatever, the Company shall pay to the Executive within 10 days
after the date of such termination any expenses for which the Executive is due
for reimbursement pursuant to the terms of the Agreement.

         7. SECTION 16 OF THE `34 ACT. The Company agrees to take all actions
necessary to provide that the issuance and conversion of the Note is exempt
under Section 16 of the `34 Act.

         8. CONFIDENTIAL INFORMATION.

         8.1. NONDISCLOSURE. The Executive shall, during the term of his
employment and at all times thereafter, treat as confidential and, except as
required in the performance of his duties and responsibilities under this
Agreement (as determined by the Executive in good faith) and except pursuant to
legal process, not disclose, publish or otherwise make available to the public
or to any individual, firm or corporation any confidential information (as
hereinafter defined).

         8.2. CONFIDENTIAL INFORMATION DEFINED. For the purposes hereof, the
term "confidential information" shall mean all information acquired by the
Executive in the course of the Executive's employment with the Company in any
way concerning the products, projects, activities, business or affairs of the
Company or the Company's customers, including, without limitation, all
information concerning trade secrets and the products or projects of the Company
and/or any improvements therein, all sales and financial information concerning
the Company, all customer and supplier lists, all information concerning
projects in research and development or marketing plans for any such products or
projects, and all information in any way concerning the products, projects,
activities, business or affairs of customers of the Company which is furnished
to the Executive by the Company or any of its agents or customers, as such;
provided, however, that the term "confidential information" shall not include
information which (a) becomes generally available to the public other than as a
result of a disclosure by the Executive, (b) was available to the Executive on a
non-confidential basis prior to his employment with the Company or (c) becomes
available to the Executive on a non-confidential basis from a source other than
the Company or any of its agents or customers provided that such source is not
bound by a confidentiality agreement with the Company or any of such agents or
customers.

         9. EQUITABLE RELIEF. In the event of a breach or threatened breach by
the Executive of any of the provisions of Section 8 of this Agreement, the
Executive hereby consents and agrees that the Company shall be entitled to an
injunction or similar equitable relief from any court of competent jurisdiction
restraining the Executive from committing or continuing any such breach or
threatened breach or granting specific performance of any act required to be






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performed by the Executive under any of such provisions, without the necessity
of showing any actual damage or that money damages would not afford an adequate
remedy and without the necessity of posting any bond or other security. Nothing
herein shall be construed as prohibiting the Company from pursuing any other
remedies at law or in equity which it may have.

         10. REPRESENTATIONS, WARRANTIES AND PROMISES OF THE COMPANY. The
Company represents and warrants to, and agrees with, the Executive as follows:

                  (i) The Company has been duly incorporated and is validly
         existing as a corporation in good standing under the laws of the State
         of Delaware.

                  (ii) The Company has duly authorized the execution and
         delivery of this Agreement and the issuance and delivery of the Note,
         and this Agreement and the Note constitute valid and legally binding
         agreements of the Company enforceable in accordance with their terms,
         except as such enforceability may be limited by bankruptcy, insolvency,
         or other laws affecting generally the enforceability of creditors'
         rights and by limitations on the availability of equitable remedies.
         The shares issuable upon conversion of the Note (the "Underlying
         Shares"), when issued and delivered in accordance with the Note, shall
         have been duly issued and shall be validly outstanding, fully paid and
         non-assessable shares of the Company's common stock, par value $0.01
         per share (the "Common Stock"). The Underlying Shares have been
         reserved for issuance by the Company.

                  (iii) Concurrently with or prior to the execution of this
         Agreement the Company has amended its Bylaws to provide that the
         President of the Company is also its Chief Executive Officer.

         10.2. REPRESENTATIONS, WARRANTIES, AND AGREEMENTS OF THE EXECUTIVE. The
Executive hereby represents and warrants to, and agrees with, the Company as
follows:

                  (i) The Executive is sufficiently experienced in financial and
         business matters to be capable of evaluating the merits and risks of
         this investment. The Executive has the financial capability for making
         the investment.

                  (ii) Prior to the execution hereof, the Executive has had the
         opportunity to ask questions of and receive answers from
         representatives of the Company concerning the finances, operations,
         business and prospects of the Company.

                  (iii) The Executive is acquiring the Note and the Underlying
         Shares for his own account for the purpose of investment and not with a
         view to, or for resale in connection with, the distribution thereof,
         nor with any present intention of distributing the Note or the
         Underlying Shares. The Executive understands that the Note and the
         Underlying Shares have


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         not been registered under the Securities Act of 1933, as amended (the
         "Securities Act") or under any applicable state securities laws, that
         the Note and the Underlying Shares may not be transferred except in
         compliance with such laws, and that the Company may affix legends on
         the note and the Underlying Shares with respect to such restrictions.

         11. REGISTRATION.

         11.1. REGISTRATION REQUESTS. Subject to the provisions of Section
11.15, the Company shall, upon the written request of the Executive (a
"Registration Request"), use reasonable efforts to file and cause to become
effective with the Securities and Exchange Commission (the "Commission"), as
soon as practicable but in no event later than sixty (60) days following receipt
of such request, a registration statement on the appropriate registration form
of the Commission (i) as shall be selected by the Company and as shall be
reasonably acceptable to the Executive, and (ii) as shall permit the resale of
some or all of the Underlying Shares in accordance with the intended method or
methods of disposition specified in the Registration Request, whether pursuant
to a delayed offering pursuant to Rule 415 under the Securities Act or otherwise
(each, a "Registration Statement"); provided, however, that the Executive shall
be entitled to only two (2) such Registration Request pursuant to this Section
11.1. Any Registration Request shall specify the number of Underlying Shares
proposed to be sold by the Executive as well as the intended method of
disposition thereof. A request for registration of Underlying Shares shall not
be considered a Registration Requests pursuant hereto unless (i) a Registration
Statement has been declared effective by the Commission, or (ii) a Registration
Statement is filed with the Commission but (A) is not declared effective as a
result of any action or inaction on the part of the Executive, or (B) is later
withdrawn at the request of the Executive. The Executive may reacquire the right
to a Registration Request lost pursuant to the previous sentence if the
Executive reimburses the Company for any and all expenses associated with such
failed registration. The Company's obligations under this Section 11.1 shall
terminate at such time as (x) the Underlying Shares beneficially owned by the
Executive consist of less than one percent (1%) of the issued and outstanding
shares of the Company and (y) the Executive has held the Note for a period of at
least one (1) year.

         11.2. PIGGYBACK REGISTRATION. If the Company proposes to file a
registration statement under the Securities Act with respect to an offering of
Common Stock for its own account or for the account of any individual,
partnership, corporation, limited liability company, joint venture, association,
joint stock company, trust, unincorporated organization, government or agency or
political subdivision thereof (each a "Person"), other than a registration
statement on Form S-4 or S-8, (or any substitute form or rule, respectively,
that may be adopted by the Commission), the Company shall give written notice of
such proposed filing to the Executive at the address set forth in Section 17
hereof as soon as reasonably practicable (but in no event less than 15 days
before the anticipated filing date), undertaking to provide the Executive the
opportunity to register on the same terms and conditions such number of
Underlying Shares as the Executive may request (a "Piggyback Registration"). The
Executive will have seven business days after receipt of any such notice to
notify the Company as to whether he wishes to participate in a Piggyback
Registration (which notice shall not be deemed to be a Registration Request);
provided that should the Executive fail to provide timely notice to the Company,
the Executive will forfeit any rights to participate in the Piggyback
Registration. In the event that






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<PAGE>   12

the registration statement is filed on behalf of a Person other than the
Company, the Company will use its reasonable best efforts to have the number of
Underlying Shares that the Executive wishes to sell included in the Registration
Statement. If the Company or the Person for whose account such offering is being
made shall determine in its sole discretion not to register or to delay the
proposed offering, the Company may, at its election, provide written notice of
such determination to the Executive and (i) in the case of a determination not
to effect the proposed offering, shall thereupon be relieved of the obligation
to register such Underlying Shares in connection therewith, and (ii) in the case
of a determination to delay a proposed offering, shall thereupon be permitted to
delay registering such Underlying Shares for the same period as the delay in
respect of the proposed offering. As between the Company and the Executive, the
Company shall be entitled to select the underwriters in connection with any
Piggyback Registration. Notwithstanding the foregoing, if the underwriters
advise the Company that such underwriters cannot purchase the number of shares
of Common Stock that all Persons desire to sell in an offering pursuant to this
Section 11.2, priority shall be given to the shares of Common Stock being sold
by the Company or other Person on whose account the offering is being made.

         11.3. PROSPECTUS DELIVERY. The Company shall as expeditiously as
possible furnish to the Executive such reasonable numbers of copies of any
prospectus, including a preliminary prospectus, in conformity with the
requirements of the Securities Act, and such other documents as the Executive
may reasonably request in order to facilitate the public sale or other
disposition of the Underlying Shares pursuant to this Section 11.

         11.4. BLUE SKY. The Company shall use its best efforts to register or
qualify the Underlying Shares covered by any Registration Statement under the
securities or Blue Sky laws of such states as the Executive shall reasonably
request, and do any and all other acts and things that may be necessary or
desirable to enable the Executive to consummate the public sale or other
disposition in such states of the Underlying Shares; provided, however, that the
Company shall not be required in connection with this Section 11.4 to qualify as
a foreign corporation or execute a general consent to service of process in any
jurisdiction.

         11.5. AMENDMENTS; SUPPLEMENTS. If the Company has delivered preliminary
or final prospectuses to the Executive and after having done so the prospectus
is amended or supplemented or required to be amended or supplemented to comply
with the requirements of the Securities Act, it shall promptly notify the
Executive and, if requested, the Executive shall immediately cease making offers
of Underlying Shares and return all prospectuses to the Company, other than file
copies. The Company shall promptly provide the Executive with amended or
supplemented prospectuses and, following receipt of the amended or supplemented
prospectuses, the Executive shall be free to resume making offers of the
Underlying Shares.

         11.6. COMPANY RECORDS. The Company shall make available for inspection
by the Executive and any attorney, accountant or other agent retained by the
Executive, all financial and other records, pertinent corporate documents and
properties of the Company, and cause the Company's officers, directors,
employees and independent accountants to supply all information reasonably
requested by any such attorney, accountant or agent in connection with such
Registration Statement.



                                       12
<PAGE>   13

         11.7. COMMISSION RULES. The Company shall comply with all applicable
rules and regulations of the Commission, and make available to its security
holders, as soon as reasonably practicable, an earnings statement covering the
period of at least twelve months beginning with the first day of the Company's
first full calendar quarter after the effective date of the Registration
Statement, which earnings statement shall satisfy the provisions of Section
11(a) of the Securities Act and Rule 158 thereunder.

         11.8. EXECUTIVE AS UNDERWRITER. If the Executive in his reasonable
judgment determines that he might be deemed to be an underwriter or a
controlling person of the Company, the Company shall permit the Executive to
participate in the preparation of any registration or comparable statement filed
pursuant herewith and to require the insertion therein of material in form and
substance satisfactory to the Executive and to the Company and furnished to the
Company in writing, which in the reasonable judgment of the Executive and his
counsel determine should be included.

         11.9. STOP ORDERS. The Company shall as expeditiously as possible
notify the Executive of the threat of issuance by the Commission of any stop
order suspending the effectiveness of any Registration Statement or the
initiation of any proceeding for that purpose, and make every reasonable effort
to prevent the entry of any order suspending the effectiveness of any
Registration Statement. In the event of the issuance of any stop order
suspending the effectiveness of any Registration Statement, or of any order
suspending or preventing the use of any related prospectus or suspending the
qualification of any Underlying Shares included in such Registration Statement
for sale in any jurisdiction, the Company will use its reasonable best efforts
promptly to obtain the withdrawal of such order.

         11.10. OPINIONS OF COUNSEL. At each closing of an underwritten
offering, the Company shall request opinions of counsel to the Company and
updates thereof (which opinions and updates shall be reasonably satisfactory to
the underwriters of the Underlying Shares being sold) addressed to the
underwriters covering the matters customarily covered in opinions requested in
underwritten offerings and such other matters as may be reasonably requested by
such sellers or their counsel.

         11.11. LISTING OF SHARES. The Company shall use its reasonable best
efforts to cause all Underlying Shares to be listed on each securities exchange
on which securities of the same class issued by the Company are then listed and
use its reasonable best efforts to qualify such Underlying Shares for trading on
each system on which securities of the same class issued by the Company are then
qualified.

         11.12. EXPENSES. Except as provided elsewhere in this Agreement, the
Company will pay all Registration Expenses for the registration of Underlying
Shares with the Commission as required under this Agreement. For purposes of
this Section, the term "Registration Expenses" shall mean all expenses incurred
by the Company in complying with this Agreement, including, without limitation,
all registration and filing fees, exchange listing fees, printing expenses, fees
and disbursements of counsel for the Company, state Blue Sky fees and expenses,
and the expense of any special audits incident to or required by any such
registration, but excluding underwriting discounts and selling commissions.




                                       13
<PAGE>   14

         11.13. INDEMNIFICATION BY COMPANY. The Company shall provide customary
indemnification to the Executive for any liability that may be incurred by the
Executive as the result of any misstatement or omission in the Registration
Statement, except insofar as such liability may arise from information provided
in writing by the Executive in his capacity as a selling stockholder under a
Registration Statement.

         11.14. INDEMNIFICATION BY EXECUTIVE. The Executive shall provide
indemnification to the Company to the same extent as the foregoing indemnity,
but only with reference to information provided in writing by the Executive in
his capacity as a selling stockholder under a Registration Statement.

         11.15. SUSPENSION OF REGISTRATION. The obligations of the Company under
this Section 11 are subject to the condition that the Company shall be entitled
to require the Executive to suspend for up to ninety (90) days once in any
twelve month period the sale of Underlying Shares pursuant to a Registration
Statement (or, if applicable, defer the filing of a Registration Statement) if
and for so long as (i) the Board determines in its reasonable judgment that the
sale of Underlying Shares pursuant thereto would materially interfere with any
material financing, acquisition, corporate reorganization or other material
transaction by the Company and (ii) the Company promptly gives the Executive
written notice of such determination. The Company shall have no obligation to
maintain the effectiveness of, or file, a Registration Statement with respect to
Underlying Shares during periods when the Executive is required to suspend the
sale of such Underlying Shares as provided in this Section 11.15. As soon as
possible after the expiration of such period, the Company shall perform all acts
necessary to permit the Executive to sell Underlying Shares pursuant to a
Registration Statement.

         12. SUCCESSORS AND ASSIGNS.

         12.1. ASSIGNMENT BY THE COMPANY. The Company shall require any
successors (whether direct or indirect, by purchase, merger, consolidation or
otherwise) to all or substantially all of the business and/or assets of the
Company to assume and agree to perform this Agreement in the same manner and to
the same extent that the Company would be required to perform if no such
succession had taken place. As used in this Agreement, the "Company" shall mean
the Company as hereinbefore defined and any successor to its business and/or
assets as aforesaid which otherwise becomes bound by all the terms and
provisions of this Agreement by operation of law and this Agreement shall be
binding upon, and inure to the benefit of, the Company, as so defined.

         12.2. ASSIGNMENT BY THE EXECUTIVE. The Executive may not assign this
Agreement or any part thereof without the prior written consent of a majority of
the Board of Directors of the Company; provided, however, that nothing herein
shall preclude one or more beneficiaries of the Executive from receiving any
amount that may be payable following the occurrence of his legal incompetence or
his death and shall not preclude the legal representative of his estate from
receiving such amount or from assigning any right hereunder to the person or
persons entitled thereto under his will or, in the case of intestacy, to the
person or persons entitled thereto under the laws of intestacy applicable to his
estate. The term "Beneficiaries", as used in this Agreement, shall mean a
beneficiary or beneficiaries so designated to receive any



                                       14
<PAGE>   15


such amount or, if no beneficiary has been so designated, the legal
representative of the Executive (in the event of his incompetence) or the
Executive's estate.

         13. GOVERNING LAW. This Agreement shall be deemed a contract made
under, and for all purposes shall be construed in accordance with, the laws of
the State of Delaware. In the event that a court of any jurisdiction shall hold
any of the provisions of this Agreement to be wholly or partially unenforceable
for any reason, such determination shall not bar or in any way affect the
Company's right to relief as provided for herein in the courts of any other
jurisdiction. Such provisions, as they relate to each jurisdiction, are, for
this purpose, severable into diverse and independent covenants. Service of
process on the parties hereto at the addresses set forth herein shall be deemed
adequate service of such process.

         14. ENTIRE AGREEMENT. This Agreement, together with the Indemnification
Agreement and then Note, contains all the understandings and representations
between the parties hereto pertaining to the subject matter hereof and
supersedes all undertakings and agreements, whether oral or in writing, if any
there be, previously entered into by them with respect thereto. The Original
Employment Agreement is superseded in its entirety by this Agreement and is no
longer of any force and effect. The Stock Purchase Agreement and the Option
Agreement, each by and between the Company and the Executive and dated as of May
5, 2000, also are no longer of any force and effect.

         15. AMENDMENT, MODIFICATION, WAIVER. No provision of this Agreement may
be amended or modified unless such amendment or modification is agreed to in
writing and signed by the Executive and by a duly authorized representative of
the Company other than the Executive. Except as otherwise specifically provided
in this Agreement, no waiver by either party hereto of any breach by the other
party hereto of any condition or provision of this Agreement to be performed by
such other party shall be deemed a waiver of a similar or dissimilar provision
or condition at the same or any prior or subsequent time, nor shall the failure
of or delay by either party hereto in exercising any right, power or privilege
hereunder operate as a waiver thereof to preclude any other or further exercise
thereof or the exercise of any other such right, power or privilege.

         16. ARBITRATION. Any dispute or controversy arising under, out of, or
in connection with or relation to this Agreement shall, at the election and upon
written demand of either the Executive or the Company, be finally determined and
settled by arbitration in the city of the Company's headquarters in accordance
with the rules and procedures of the American Arbitration Association, and
judgment upon the award may be entered in any court having jurisdiction thereof.
Any fees, costs or expenses incurred by Executive in connection with any such
arbitration shall be paid by the Company, as such fees, costs or expenses are
incurred, within 10 days after receipt by the Company of invoices or other
reasonable documentation evidencing such fees, costs or expenses; provided,
however, that all such fees, costs or expenses shall be reimbursed to the
Company if the finder of fact determines that the Company is the prevailing
party in such arbitration.

         17. NOTICES. Any notice to be given hereunder shall be in writing and
delivered personally or sent by certified mail, postage prepaid, return receipt
requested,





                                       15
<PAGE>   16

addressed to the party concerned at the address indicated below or at such other
address as such party may subsequently designate by like notice:

          If to the Company:

                 NAHC, Inc.
                 1018 West Ninth Avenue
                 King of Prussia, Pennsylvania  19406
                 Attention:  President, with a copy to the Chairman of the Board

                 with an additional copy to:

                 James Giddens, Esq.
                 Hughes, Hubbard & Reed
                 Battery Park Plaza
                 New York, NY 10004-1482

          If to the Executive:

                 David R. Burt
                 259 Granville Lane
                 North Andover, MA 01845
                 with one copy sent to davburt@msn.com

          With a copy to:

                 Michael D. Wortley
                 Vinson & Elkins L.L.P.
                 3700 Trammell Crow Center
                 2001 Ross Avenue
                 Dallas, TX  75201

         18. SEVERABILITY. Should any provision of this Agreement be held by a
court or arbitration panel of competent jurisdiction to be enforceable only if
modified, such holding shall not affect the validity of the remainder of this
Agreement, the balance of which shall continue to be binding upon the parties
hereto with any such modification to become a part hereof and treated as though
originally set forth in this Agreement. The parties further agree that any such
court or arbitration panel is expressly authorized to modify any such
unenforceable provision of this Agreement in lieu of severing such unenforceable
provision from this Agreement in its entirety, whether by rewriting the
offending provision, deleting any or all of the offending provision, adding
additional language to this Agreement, or by making such other modifications as
it deems warranted to carry out the intent and agreement of the parties as
embodied herein to the maximum extent permitted by law. The parties expressly
agree that this Agreement as so modified by the court or arbitration panel shall
be binding upon and enforceable against each of them. In any event, should one
or more of the provisions of this Agreement be held to be invalid, illegal or
unenforceable in any respect, such invalidity, illegality or unenforceability
shall not affect any other provisions hereof, and if such provision or
provisions


                                       16
<PAGE>   17


are not modified as provided above, this Agreement shall be construed as if such
invalid, illegal or unenforceable provisions had never been set forth herein.

         19. SURVIVORSHIP. The respective rights and obligations of the parties
hereunder shall survive any termination of the Executive's employment to the
extent necessary to the intended preservation of such rights and obligations.

         20. HEADINGS. Headings of the sections and paragraphs of this Agreement
are intended solely for convenience and no provision of this Agreement is to be
construed by reference to the title of any section or paragraph.

         21. COUNTERPARTS. This Agreement may be executed in counterparts, each
of which shall be deemed an original, but all of which taken together shall
constitute one and the same instrument.



                [Remainder of this page left blank intentionally]



                                       17
<PAGE>   18



         IN WITNESS WHEREOF, the parties hereto have executed this Agreement as
of the date first above written.

                                          NAHC, INC.



                                          By
                                             ----------------------------------
                                              Name:
                                              Title:



                                          By
                                             ----------------------------------
                                              David R. Burt




The foregoing Agreement has been
Approved by the Compensation Committee
of the Board of Directors:


----------------------------------
Stephen E. O'Neil
Chairman of Compensation Committee





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