<PAGE>   1
                                                                   EXHIBIT 10.15


                                    ADDENDUM

THIS ADDENDUM ("Addendum") entered into this 1st day of March, 1999, by and
between Net Command Tech, Inc., a Delaware corporation ("Company") with offices
at 62 Indian Trace, Weston, Florida 33326 and William R. Dunavant
("Executive"), with an address of 2461 Provence Circle, Weston, Florida 33327.


                             W I T N E S S E T H :


WHEREAS, the Company and the Executive have entered into an Employment
Agreement ("Agreement") on this same date; and

WHEREAS, the Company and Executive have agreed that this Addendum shall form a
part of the Agreement;

NOW, THEREFORE, in consideration of the mutual promises contained herein and in
the Agreement and other good and valuable consideration, the receipt and
sufficiency of which is hereby acknowledged, the parties agree as follows:

1.   PRECEDENCE AND INCORPORATION. This Addendum forms a part of the Agreement
attached. The Agreement and this Addendum shall be considered one document. The
terms contained in this Addendum shall take precedence over any Agreement terms
that are inconsistent with this Addendum. Terms used in this Addendum shall
have the same meaning as ascribed to them in the Agreement.

2.   INTERIM BASE SALARY REVIEW. Executive's Base Salary shall be reviewed for
an interim increase on January 1, 2000.

3.   SEPARATION PAY. Executive shall be entitled to receive twelve (12) month's
pay as separation pay in the event of Executive's termination of employment
with the Company, so long as Executive is not terminated with cause, as that
term is defined in Paragraph 6 of the Agreement. Executive shall also receive
any bonus earned (pro-rata) at the time of termination, so long as Executive is
not terminated without cause, as that term is defined in Paragraph 6 of the
Agreement. Payment shall be made, in the Company's sole discretion, in a lump
sum or periodic payments over six months. Executive's life, medical, and other
insurance coverages shall be maintained at the Company's expense for a period
of twelve (12) months or until such time that Executive obtains new full time
employment, so long as Executive is not terminated without cause, as that term
is defined in Paragraph 6 of the Agreement. Additionally, the Company vehicle
provided to Executive under Paragraph 6E shall be purchased by the Company and
given/titled to Dunavant, so long as Executive is not terminated with cause,
as that term is defined in Paragraph 6 of the Agreement.

The Company has no severance pay policy or plan and this separation pay shall
not be considered severance pay. However, this paragraph 3 shall survive
termination of the Agreement, provided that it is not terminated under
Paragraph 6 of the Agreement.
<PAGE>   2
4.   STOCK ISSUANCE. Executive shall be issued two million shares (2,000,000)
shares of the Company's common stock at a price of $.001 per share upon
execution of this Agreement. These shares shall be registered by the Company if
Executive is terminated without cause.

5.   STOCK OPTIONS. During each year Executive is employed by the Company,
Executive shall receive cashless options exercisable at $5.00 per share, equal
in value to five-percent (5%) of the Company's gross sales for that year. Should
Executive be terminated without cause, or terminated or demoted because of a
corporate reorganization and/or takeover/acquisition, or should there be a
change in control of fifty-one-percent (51%) or more by a single shareholder or
shareholder group (all these described events collectively defined as ("Control
Event"), all options accrued at the time of the Control Event shall vest
immediately at the rate described above for the gross sales at the time of the
Control Event, or five-percent (5%) of the price paid for the change in control
(as calculated by an independent professional appraiser), whichever is greater.
Executive shall also participate in the Company's Incentive Stock Option
Program.

6.   BENEFITS. Executive shall receive the following fringe benefits in
addition to his base benefits, which shall be vested upon Executive's
commencement of employment with the Company:

               A.   Four weeks paid vacation during the first year of the
Initial Term. Five weeks paid vacation each year thereafter. Unused vacation
days in any year can be carried over and accumulated to subsequent years.

               B.   Six (6) personal/six days each year and up to six days off
per year for national holidays, such holidays being in addition to vacation
days.

               C.   Health Insurance (PPO), Dental Insurance, Disability
Insurance, and Life Insurance in the amount of $1,000,000.00 for Executive and
his dependents. Company shall pay the premiums required for these coverages on
Executive only.

               D.   Participation in the Company's 401K Plan, with matching
contributions made annually by the Company up to two-percent (2%) of
Executive's Base Salary for each year.

               E.   A Company vehicle, leased not to exceed $800 per month,
with the Company paying all lease, gasoline, maintenance and insurance costs.

               F.   Club membership fees up to a maximum of $3,500 per year.

               G.   Tax accounting reimbursement up to $1,500 per year, for
personal advisory services regarding Company stock and income tax filing.

               H.   Company shall pay Executive's attendance at seminars and
conferences that will enhance the Company's reputation, standing, or
profitability. Attendance at the described events shall not be categorized as
sick, personal, or vacation days.




                                       2
<PAGE>   3
7.   RELOCATION. If Executive agrees to a relocation from his present
employment locale and domicile, Company shall reimburse Executive for all
relocation expenses typical for executives, including domicile closing costs,
points and commissions, with the intent that executive does not incur any
financial loss in the overall cost of the relocation, with the exception of
purchase and sale prices of his changes in domiciles.

8.   COUNTERPARTS. This Addendum may be executed in counterparts, each of which
shall be deemed an original. All such counterparts together shall constitute
one and the same Agreement.

IN WITNESS WHEREOF, the parties hereto have caused this Addendum to be executed
as of the date first written above.


NET COMMAND TECH, INC.                          "Executive"

By: /s/ William R. Dunavant                      /s/ William R. Dunavant
   ----------------------------                 -----------------------------
    William R. Dunavant                          William R. Dunavant
    President




                                       3