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                                                                   EXHIBIT 10.74

SOURCE CAPITAL GROUP, INC.
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Members NASD, SIPC           Investment Bankers/Brokers            sourcegrp.com



                                                                    July 9, 2003


Mr. Steve Michael
President
Invisa, Inc.
4400 Independence Court
Sarasota, FL 34234


Dear Mr. Michael

The purpose of this letter is to confirm the understanding and agreement (the
"Agreement") between Source Capital Group, Inc. ("SCG") and Invisa, Inc. (or
the "Company"), regarding the retention of SCG by the Company as its
non-exclusive financial advisor for the purposes set forth herein.

Under this Agreement, SCG will provide financial advisory services to the
Company as follows:

         A)       Raising of Capital.  SCG shall use its best efforts to provide
                  an equity financing for the Company.

         B)       Fees, Commissions & Expenses.  The Company agrees to pay the
                  following fees to SCG for its services.

                  1.       SCG will be compensated 8% cash and 8% ("warrant")
                           coverage on any funds raised during this engagement
                           and introduced by SCG. The exercise price of the
                           warrants shall be equal to the market price of the
                           stock at the time of the sale and will be subject to
                           adjustment in accordance with the terms of any
                           adjustment provided for in the Financing document.
                           Said warrants shall be exercisable for five (5) years
                           from date of issuance. The terms of said warrants
                           shall include one piggyback registration right,
                           anti-dilution rights, and "cashless" (when no
                           registration statement is not in effect) exercise
                           provisions in the event of exercise by SCG. Such fees
                           shall be paid at the closing from an escrow account
                           at the same time any new investment is dispersed to
                           the company. The compensation shall be limited to
                           investments that are closed and funded. The Company
                           shall have sole discretion to accept or reject any
                           financing or investment introduced by SCG. The
                           compensation shall be paid as and in the same manner
                           as such investment is funded. In the event of debt
                           (as opposed to an equity investment) the
                           consideration shall be 3% (in lieu of 8%) and in the
                           event of a merger or acquisition, the



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Source Capital Group, Inc.                                           Page 2 of 6



                           consideration shall be a cash fee (only) based on
                           the Lehman formula (in lieu of 8%).

                  2.       SCG will receive 5000 shares as a retainer upon
                           signing of this agreement. The shares shall be
                           restricted and shall be included in the Company's
                           next registration statement.

                  3.       Expenses.  In addition to any fees that may be
                           payable to SCG under this Agreement, the Company
                           agrees to reimburse SCG for its reasonable
                           out-of-pocket expenses that are approved in advance
                           by the Company in writing and that are incurred in
                           connection with the services rendered by SCG
                           hereunder (including, without limitation, travel and
                           lodging, data and word processing, graphics and
                           communication charges, research costs, and courier
                           services and fees). SCG will, on a monthly basis,
                           provide the Company with reasonable report regarding
                           the expenses incurred. Compensation for any
                           additional professional services (e.g. legal or
                           consulting) contracted for by SCG, to be performed
                           for the benefit of the Company by outside parties, is
                           the responsibility of the Company and will be paid
                           directly by the Company to such party. SCG will not
                           contract for such services without the prior written
                           approval of the Company with regard to both the
                           nature of the service and a reasonable estimate of
                           the cost of such service.

                  4.       All cash payments under this Agreement shall be made
                           in U.S. dollars and without withholding or deduction
                           of any tax, assessment or other governmental charges
                           unless required by law. Fees and retainers should be
                           made payable and wired to:

                           Source Capital Group, Inc.
                           Fleet Bank
                           ABA# 011900571
                           Acct.# 9361882644

         C)       Information.  The Company will furnish or cause to be
                  furnished to SCG, such information, as SCG believes
                  appropriate to its assignment (all such information so
                  furnished being the "Information"). The Company recognizes and
                  confirms that SCG (a) will use and rely primarily on the
                  Information and on information available from generally
                  recognized public sources in performing the services
                  contemplated by this Agreement without having independently
                  verified the same, (b) does not assume responsibility for the
                  accuracy or completeness of the Information and such other
                  information, (c) is entitled to rely upon the Information
                  without independent verification and (d) will not make an
                  appraisal of any assets in connection with its assignment.

         D)       Confidentiality.  Except as contemplated by the terms hereof
                  or as required by applicable law or legal process, SCG shall
                  keep confidential all non-public information provided to it by
                  or at the request of the Company, and shall not disclose such
                  information to any third party or to any of its employees or
                  advisors except to those persons who have a need


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Source Capital Group, Inc.                                           Page 3 of 6


         to know such information in connection with SCG's performance of its
         responsibilities hereunder. The Company understands that any documents,
         presentations or analyses prepared by SCG are proprietary and SCG is
         under no obligation to provide (by e-mail, floppy disk or otherwise)
         either the Company or its assigns with the computer files of such work
         product. Except as required by applicable law, any advice to be
         provided by SCG under this Agreement shall not be disclosed publicly or
         made available to third parties without the prior written consent of
         SCG. In addition, SCG may not be otherwise publicly referred to without
         its prior written consent. All services, advice and information and
         reports provided by SCG to the Company in connection with this
         assignment shall be for the sole benefit of the Company and shall not
         be relied upon by any other person.

E)       Indemnity.  The Company acknowledges and agrees that SCG has been
         retained to act solely as financial advisor to the Company. In such
         capacity, SCG shall act as an independent contractor, and any duties of
         SCG arising out of its engagement pursuant to this Agreement shall be
         owed solely to the Company. The Company agrees to indemnify SCG in
         accordance with the indemnification agreement attached as Exhibit A.

F)       Arbitration.  Any and all disputes, demands, claims or controversies
         hereto arising out of or relating to this agreement or the breach
         thereof, shall be settled binding arbitration in accordance with the
         rules of the American Arbitration Association ("AAA"). The arbitration
         shall be conducted in New York City under the rules of the AAA. Any
         judgment upon the award rendered by the arbitrator may be entered into
         any court or administrative tribunal having jurisdiction thereof. Costs
         associated with the arbitration, including reasonable attorney's fees,
         shall be borne by whichever parties the arbitrators shall deem just and
         fair."

G)       Term & Termination.  The term of SCG's engagement hereunder shall
         extend from the date hereof through Sept. 30, 2003 (the "Expiration
         Date") and will be automatically renewed on a monthly basis until
         canceled in writing by either party. SCG's engagement hereunder may be
         terminated upon 10 days written notice without cause by either the
         Company or SCG at any time before the Expiration Date. Notwithstanding
         the foregoing, the provisions relating to the payment of fees and
         expenses accrued through the date of termination, the status of SCG as
         an independent contractor and the limitation on to whom SCG shall owe
         any duties will survive any such termination, and any such termination
         shall not affect the Company's obligations under the indemnification
         agreement.

         SCG will be entitled to the fees set forth above in the event that at
         any time prior to the earlier of the termination of this letter and the
         expiration of SCG's engagement hereunder a Financing is consummated and
         the investor is on a list of potential investors provided to the
         Company by SCG at the time of termination or expiration and SCG had
         made efforts that led to an investment on behalf of the Company with
         respect to such investor(s) prior to termination or expiration, as
         appropriate. Further, in the event that a Financing or M&A transaction
         is completed with an investor, on the list described above, with
         respect to which SCG had made efforts that led directly to an
         investment or other substantive effort before such termination or
         expiration, whichever is earlier, SCG will be entitled to fees on those
         investors (but only for the amount purchased by such investors) for a
         period


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Source Capital Group, Inc.                                           Page 4 of 6


                  of 18 months after the termination or expiration date, as
                  applicable, calculated in accordance with Section B of this
                  Agreement. On the termination or expiration date, as
                  applicable, SCG will provide the Company an updated EXHIBIT B
                  for purposes of this paragraph.

         H)       ADVERTISEMENTS. The Company acknowledges that SCG may, at its
                  option and expense, place an announcement in such newspapers
                  and periodicals as it may choose, stating that SCG has acted
                  as the financial advisor to the Company. SCG agrees that the
                  Company will have the right to approve the form of such
                  announcement.

This Agreement (including the attached indemnification) embodies the entire
agreement and understanding between the parties hereto and supersedes all prior
agreements and understandings relating to the subject matter hereof. If any
provision of this Agreement is determined to be invalid or unenforceable in
any respect, such determination will not affect such provision in any other
respect, which will remain in full force and effect. No waiver, amendment or
other modification of this Agreement shall be effective unless in writing and
signed by each party to be bound thereby. This Agreement shall be governed by,
and construed in accordance with, the laws of the State of New York applicable
to contracts executed in and to be performed in that state.

This Agreement sets forth the entire agreement with respect to the engagement
of SCG by the Company, including the fees and warrants payable as a result of
such engagement.

Please confirm that the foregoing correctly sets forth our agreement by signing
and returning to SCG the duplicate copy of this Agreement, the indemnification
agreement attached hereto as EXHIBIT A.


                                           By: /s/ W. Todd Coffin
                                               ---------------------------------
                                               W. Todd Coffin, Managing Director
                                               Source Capital Group, Inc.

By: /s/ Steve Michael
    ----------------------------------
    Steve Michael, President
    Invisa, Inc.





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Source Capital Group, Inc.                                         Page 5 of 6


This EXHIBIT A is a part of and is incorporated into that certain letter
agreement, July 9, 2003 (the "Agreement"), by and between Invisa, Inc., a Nevada
corporation (with its wholly-owned subsidiaries collectively, the "Company"),
and Source Capital Group, Inc. (the "Placement Agent"). Capitalized terms used
herein and not otherwise defined shall have the respective meanings provided in
the Agreement.

THE COMPANY AGREES TO INDEMNIFY AND HOLD HARMLESS THE PLACEMENT AGENT, ITS
AFFILIATES AND EACH PERSON CONTROLLING THE PLACEMENT AGENT AND THE PLACEMENT
AGENT AGREES TO INDEMNIFY AND HOLD HARMLESS THE COMPANY (within the meaning of
Section 15 of the Securities Act), and the directors, officers, agents and
employees of the Placement Agent, its affiliates and each such controlling
person (the Placement Agent, and each such entity or person, an "Indemnified
Person") from and against any losses, claims, damages, judgments, assessments,
costs and other liabilities (collectively, the "Liabilities"), and shall
reimburse each Indemnified Person for all fees and expenses (including the
reasonable fees and expenses of one counsel for all Indemnified Persons, except
as otherwise expressly provided herein) (collectively, the "Expenses") as they
are incurred by an Indemnified Person in investigating, preparing, pursuing or
defending any claim, action, proceeding or investigation, whether or not any
Indemnified Person is a party thereto (collectively, the "Actions"), (i) caused
by, or arising out of or in connection with, any untrue statement or alleged
untrue statement of a material fact contained in any offering documents prepared
by the Company (including any amendments thereof and supplements thereto) (the
"Offer Documents") or by any omission or alleged omission to state therein a
material fact necessary to make the statements therein, in light of the
circumstances under which they were made, not misleading (other than untrue
statements or alleged untrue statements in, or omissions or alleged omissions
from, information relating to an Indemnified Person furnished in writing by or
on behalf of such indemnified Person expressly for use in the Offer Documents)
or (ii) otherwise arising out of or in connection with advice or services
rendered or to be rendered by any Indemnified Person pursuant to the Agreement,
the transactions contemplated thereby or any Indemnified Person's actions or
inactions in connection with any such advice, services or transactions;
provided, however, that, in the case of clause (ii) only, the Company shall not
be responsible for any Liabilities or Expenses of any Indemnified Person that
have resulted primarily from such Indemnified Person's (x) gross negligence, bad
faith or willful misconduct in connection with any of the advice, actions,
inactions or services referred to above or (y) use of any offering materials or
information concerning the Company in connection with the offer or sale of the
Securities in the Transaction which were not authorized for such use by the
Company and which use constitutes negligence, bad faith or willful misconduct.
The Company also agrees to reimburse each Indemnified Person for all Expenses as
they are incurred in connection with enforcing such Indemnified Person's rights
under the Agreement, which includes this EXHIBIT A.

Upon receipt by an Indemnified Person of actual notice of an Action against such
Indemnified Person with respect to which indemnity may be sought under the
Agreement, such Indemnified Person shall promptly notify the Company in writing;
provided that failure by any Indemnified Person so to notify the Company shall
not relieve the Company from any liability which the Company may have on account
of this indemnity or otherwise to such Indemnified Person, except to the extent
the Company shall have been prejudiced by such failure. The Company shall, if
requested by the Placement Agent, assume the defense of any such Action
including the employment of counsel reasonably satisfactory to the Placement
Agent, which counsel may also be counsel to the Company. Any Indemnified Person
shall have the right to employ separate counsel in any such action and
participate in the defense thereof, but the fees and expenses of such counsel
shall be at the expense of such Indemnified Person unless: (i) the Company has
failed promptly to assume the defense and employ counsel or (ii) the named
parties to any such Action (including any impeded parties) include such
Indemnified Person and the Company, and such Indemnified Person shall have been
advised in the reasonable opinion of counsel that there is an actual conflict of
interest that prevents the counsel selected by the Company from representing
both the Company (or another client of such counsel) and any Indemnified Person;
provided that the Company shall not in such event be responsible hereunder for
the fees and expenses of more than one firm of separate counsel for all
Indemnified Persons in connection with any Action or related Actions, in
addition to any local counsel. The Company shall not be liable for any
settlement of any Action effected without its written consent (which shall not
be unreasonably withheld). In addition, the Company shall not, without the prior
written consent of the Placement Agent (which shall not be unreasonably
withheld), settle, compromise or consent to the entry of any judgment in or
otherwise seek to terminate any pending or threatened Action in respect of which
indemnification or contribution may be sought hereunder (whether or not such
Indemnified Person is a party thereto) unless such settlement, compromise,
consent or termination includes an unconditional release of each Indemnified
Person from all Liabilities arising out of such Action for which

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Source Capital Group, Inc.                                         Page 6 of 6


indemnification or contribution may be sought hereunder. The indemnification
required hereby shall be made by periodic payments of the amount thereof during
the course of the investigation or defense, as such expense, loss, damage or
liability is incurred and is due and payable.

In the event that the foregoing indemnity is unavailable to an Indemnified
Person other than in accordance with the Agreement, the Company shall contribute
to the Liabilities and Expenses paid or payable by such Indemnified Person in
such proportion as is appropriate to reflect (i) the relative benefits to the
Company, on the one hand, and to the Placement Agent and any other Indemnified
Person, on the other hand, of the matters contemplated by the Agreement, or (ii)
if the allocation provided by the immediately preceding clause is not permitted
by applicable law, not only such relative benefits but also the relative fault
of the Company, on the one hand, and the Placement Agent and any other
Indemnified Person, on the other hand, in connection with the matters as to
which such Liabilities or Expenses relate, as well as any other relevant
equitable considerations; provided that in no event shall the Company contribute
less than the amount necessary to ensure that all Indemnified Persons, in the
aggregate, are not liable for any Liabilities and Expenses in excess of the
amount of fees actually received by the Placement Agent pursuant to the
Agreement. For purposes of this paragraph, the relative benefits to the Company,
on the one hand, and to the Placement Agent on the other hand, of the matters
contemplated by the Agreement shall be deemed to be in the same proportion as
(a) the total value paid or contemplated to be paid to or received or
contemplated to be received by the Company in the transaction or transactions
that are within the scope of the Agreement, whether or not any such transaction
is consummated, bears to (b) the fees paid to the Placement Agent under the
Agreement. Notwithstanding the above, no person guilty of fraudulent
misrepresentation within the meaning of Section 11(f) of the Securities Act of
1933, as amended, shall be entitled to contribution from a party who was not
guilty of fraudulent misrepresentation.

The Company also agrees that no Indemnified Person shall have any liability
(whether direct or indirect, in contract or tort or otherwise) to the Company
for or in connection with advice or services rendered or to be rendered by any
Indemnified Person pursuant to the Agreement, the transactions contemplated
thereby or any Indemnified Person's actions or inactions in connection with
any such advice, services or transactions except for Liabilities (and related
Expenses) of the Company that have resulted primarily from such Indemnified
Person's gross negligence, bad faith or willful misconduct in connection with
any such advice, actions, inactions or services.

The reimbursement, indemnity and contribution obligations of the Company set
forth herein shall apply to any modification of the Agreement and shall remain
in full force and effect regardless of any termination of, or the completion of
any Indemnified Person's services under or in connection with, the Agreement.






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