Exhibit 10.31

                                 PROMISSORY NOTE


$50,000.00                                                       APRIL 19, 2002

ULTRASTRIP SYSTEMS, INC., a Florida corporation ("Maker") (Maker and each
endorser, surety or guarantor, are collectively herein called "Obligor"),
promises to pay to the order of MICHAEL CRISTOFORO ("Lender"; Lender and each
and all subsequent holders of this note are included in the terms "Holder"), at
3515 SOUTHEAST LIONEL TERRACE, STUART, FLORIDA, 34997(or at such other place as
the Holder hereof may designate), the sum of FIFTY THOUSAND AND 00/100 DOLLARS
($50,000.00) with interest at the Applicable Interest Rate, as defined below.
Interest on principal will accrue at the Applicable Interest Rate from April 19,
2002 at the rate of 1/360th of annual interest for each day that principal is
outstanding; provided, however, in no event shall interest be due at a rate in
excess of the maximum permissible legal rate.

Principal and interest shall be payable as follows:

         a.       The entire outstanding principal balance of note, together
                  with all accrued but unpaid interest thereon, shall be due and
                  payable in full on April 19, 2003 (the "Maturity Date").

         b.       The "Applicable Interest Rate" shall mean the rate per annum
                  which is 2 % per annum in excess of the fluctuating prime rate
                  announced or established from time to time by Northern Trust
                  (the "Bank"), accruing on a 360-day basis on outstanding
                  principal. The prime rate is a reference rate only, and is not
                  necessarily the lowest or best rate offered by Bank for loans
                  to its borrowers. The Applicable Interest Rate shall
                  automatically adjust on each date that the Bank adjusts its
                  prime rate.

         c.       This note may be prepaid at any time in whole or in part,
                  without premium or penalty.

As used in this instrument, the term "Obligations" shall refer to the
indebtedness represented by this note and all modifications, renewals and
substitutions hereof.

The happening of any of the following events shall constitute a default
hereunder: (1) a failure of any Obligor to pay in full any installment payable
hereunder promptly when it becomes due; (2) failure of any Obligor to pay in
full when due any indebtedness, obligation, or liability to the Holder
whatsoever, or any installment thereof or interest thereon; (3) failure of any
Obligor to perform any agreement hereunder; (4) the Holder learns that any
warranty, representation, certificate or statement of any Obligor (whether
contained in this note or not) pertaining to or in connection with this note or
the loan or credit evidenced by this note, is not true; (5) any Obligor becomes
insolvent or any insolvency proceedings (as said terms "insolvent" and

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"insolvency proceedings" are defined in the Uniform Commercial Code of Florida)
are instituted or made by or against any Obligor, or application is made for the
appointment of a receiver for any Obligor or for any of the assets of any
Obligor; (6) the entry of a judgment against any Obligor; (7) the issuing of any
levy, attachment or garnishment, or the filing of any lien against any property
of any Obligor; or (8) the dissolution, merger, consolidation, or reorganization
of any Obligor.

Upon the happening of any default as defined herein the entire amount of this
note remaining unpaid, shall, at the option of the Holder and without notice or
demand, become due and payable forthwith or thereafter. In the event of any
default hereunder, after deducting any paid and unaccrued or paid and unearned
interest from the principal balance then due, the then unpaid principal balance
hereof and any accrued and unpaid interest shall bear interest from the time of
such default at the maximum legal rate permissible (the "Default Rate"), and,
regardless of the payment terms of the note, and all unpaid interest from the
time of such default may be compounded on a monthly basis, the first such
compounding to be made 30 days after the default and, thereafter, on the same
date of each subsequent month until all Obligations have been paid in full. In
no event and under no circumstances shall there be due hereunder, nor shall the
Holder be entitled hereunder to receive at any time, any charges not allowed or
permitted by law or any interest or interest rate in excess of the maximum
allowed by law. In the event that the amount of any charge or payment due
hereunder shall create or shall be deemed to create an interest charge in excess
of the maximum permissible legal rate, then the charge of any such excess amount
shall be deemed unenforceable and void and its collection shall be waived,
without affecting the remainder of the Obligations evidenced hereby, and any
such excess amount which may have been paid to the Holder shall be refunded.

In the event the Holder shall be required at any time to pay documentary stamp
tax, intangible tax, or other taxation with respect to all or part of the Loan
or any other transaction contemplated or evidenced by this note, the Obligor
shall reimburse the Holder immediately for all such costs, including any
interest and penalties with respect thereto.

With respect to any and all Obligations, the Obligors severally waive the
following: (1) demand, presentment, protest, notice of dishonor, suit against
any party and all other requirements necessary to charge or hold any Obligor
liable on any Obligation; (2) any further receipt for or acknowledgment of the
Collateral now or hereafter deposited or statement of indebtedness; (3) the
right to interpose any set-off or counterclaim of any nature or description in
any litigation in which the Holder and any Obligor shall be adverse parties. The
Obligors severally agree that any Obligations of any Obligor may, from time to
time, in whole or in part, be renewed, extended, modified, accelerated,
compromised, discharged or released by the Holder, all without notice to or
further reservations of rights against any Obligor and all without in any way
affecting or releasing the liability of any Obligor. The Obligors jointly and
severally agree to pay all taxes and assessments levied on or with respect to
the Obligations, this note, including but not limited to intangible and
documentary stamp taxes, and all filing fees and taxes and all costs of
collecting or securing or attempting to collect or secure any Obligations,
including attorneys' fees, whether or not involving litigation and/or appellate
proceedings.

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The Holder shall not by any act, delay, omission or otherwise be deemed to have
waived any of its rights or remedies, and no waiver of any kind shall be valid,
unless in writing and signed by the Holder. All rights and remedies of the
Holder under the terms of this note and under any statutes or rules of law shall
be cumulative and may be exercised successively or concurrently. The Obligors
jointly and severally agree that the Holder shall be entitled to all the rights
of a holder in due course of a negotiable instrument. This note shall be
governed by and construed in accordance with the laws of the State of Florida.
Any provision of this note which may be unenforceable or invalid under any law
shall be ineffective to the extent of such unenforceability or invalidity
without affecting the enforceability or validity of any other provision hereof.
Any notice required to be given to any person shall be deemed sufficient if
mailed, postage prepaid, to such person's address as it appears on this note,
or, if none appears, to any address in the Holder's files. The Holder shall have
the right unilaterally to correct patent errors in this note and to fill in any
blank spaces herein so as to conform to the terms upon which the loan evidenced
hereby is made.

The Obligors shall be jointly and severally liable for all indebtedness
represented by this note and have subscribed their names hereto without
condition that anyone else should sign or become bound hereon and without any
other condition whatever being made. The provisions of this note are binding on
the heirs, executors, administrators, assigns and successors of each and every
Obligor and shall inure to the benefit of the Holder, its successors and
assigns. This note is executed under the seal of each of the Obligors.

This promissory note constitutes and evidences the complete understanding
between the Holder and the Obligors. All prior and contemporaneous discussions
between the Holder and the Obligor, including all representations and promises
by the Holder, whether oral or written, concerning the Obligations, are included
in and merged in this note. Any modification thereof hereafter which is not in
writing and signed by the Holder and the Obligor shall be void, except that the
Holder may in its sole discretion extend the maturity of the loan evidenced by
this note for a term specified in a written notification mailed to the Obligor
at its address shown on the Holder's records. The Holder may rely on the
information, instructions, or other communications (including requests for and
directions concerning loan advances) given to the Holder by any one Obligor.

Notwithstanding anything herein to the contrary, Holder agrees, by acceptance
of this note, to forbear acceleration of the unpaid principal balance hereof (a)
for a period of 10days for the failure of the Obligor to make a payment when due
hereunder. Such forbearance shall not deny or in any way mitigate the occurrence
of a default, unless the Obligor, within the applicable forbearance period,
cures such default to Holder's satisfaction, in which event the Loan shall
thereupon be reinstated and restored to good standing in all respects, including
the interest rate hereon, effective as of the date of the default.

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No invalid provision of this note shall affect or impair any other provision.
Maker and each other Obligor acknowledge receipt of a completed copy of this
Note.

THE OBLIGOR AND, BY ITS ACCEPTANCE HEREOF, THE HOLDER, EACH HEREBY WAIVES (1)
ALL RIGHTS TO RELY ON OR ENFORCE ANY ORAL STATEMENTS MADE PRIOR TO,
CONTEMPORANEOUSLY WITH OR SUBSEQUENT TO THE SIGNING OF THIS PROMISSORY NOTE; AND
(2) THE RIGHT EITHER MAY HAVE TO A TRIAL BY JURY WITH RESPECT TO ANY LITIGATION
ARISING OUT OF, UNDER OR IN CONNECTION WITH THIS PROMISSORY NOTE, OR WITH
RESPECT TO DEALINGS BETWEEN THE HOLDER AND THE OBLIGOR CONCERNING ANY COURSE OF
CONDUCT, STATEMENTS (WHETHER VERBAL OR WRITTEN) OR ACTIONS OF EITHER PARTY. THIS
PROVISION IS A MATERIAL INDUCEMENT FOR THE HOLDER TO PROVIDE CREDIT TO THE
OBLIGOR.


                                        UltraStrip Systems, Inc.

                                        By: /s/ Robert O. Baratta
                                            --------------------------------
                                        Its:     Pres. / CEO