<PAGE>

                                                                    EXHIBIT 10.4

                                   PROMISSORY NOTE
<TABLE>
<CAPTION>
-----------------------------------------------------------------------------------------
 Principal    Loan Date   Maturity   Loan No.  Call  Collateral  Account  Office  Initial
<S>          <C>         <C>         <C>       <C>   <C>         <C>      <C>     <C>
$100,000.00  07-16-1999  01-16-2000   3035218   522      522      107799   JIMS
-----------------------------------------------------------------------------------------
References in the shaded area are for Lender's use only and do not limit the applicability
of this document to any particular loan or item.
    Any items above containing """"" has been omitted due to text length limitations.
-----------------------------------------------------------------------------------------

</TABLE>

Borrower: Heartsoft Software Company    Lender:   Tulsa National Bank
          (TIN: 73-1391467)                       7120 S. Lewis
          3101 North hemlock Circle               P.O. Box 1051
          Broken Arrow, OK 74012                  Tulsa, Ok 74136
                                                  (918) 484-4884

<TABLE>
-----------------------------------------------------------------------------------------
<S>                <C>          <C>            <C>     <C>           <C>
Principal Amount:  $100,000.00  Initial Rate:  9.250%  Date of Note: July 16, 1999

</TABLE>

PROMISE TO PAY:  Heartsoft Software Company ("Borrower") promises to pay to
Tulsa National Bank ("Lender"), or order, in lawful money of the United
States of America, the principal amount of One Hundred Thousand & 00/100
Dollar ($100,000.00) or so much as may be outstanding, together with interest
on the unpaid outstanding principal balance of each advance.  Interest shall
be calculated from the date of each advance until repayment of each advance.

PAYMENT:  Borrower will pay this loan in one payment of all outstanding
principal plus all accrued unpaid interest on January 16, 2000.  In addition,
Borrower will regular monthly payments of all accrued unpaid interest due as
of each payment date, beginning August 16, 1999, with all subsequent interest
payments to be due on the same day of each month after that.  Unless
otherwise agreed or required by applicable law, payments will be applied
first to accrued unpaid interest, then to principal, and any remaining amount
to any unpaid collection costs.  The annual interest rate for this Note is
computed on a 365/360 basis; that is, by applying the ratio of the annual
interest rate over a year of 360 days, multiplied by the outstanding
principal balance, multiplied by the actual number of day the principal
balance is outstanding.  Borrower will pay Lender at Lender's address shown
above or at such other place as Lender may designate in writing.

VARIABLE INTEREST RATE:  The interest rate on this Note is subject to change
from time to time based on changes in any independent index, which is the
Prime Interest rate as published in the money section of the Wall Street
Journal (the "Index"). The Index is not necessarily the lowest rate charged
by Lender on its loans.  If the Index becomes unavailable during the term of
this loan, Lender may designate a substitute index after notice to Borrower.
Lender will tell Borrower the current index rate upon Borrower's request.
The interest rate change will not occur more often than each Day.  Borrower
understands that Lender may make loans based on other rates as well.  The
Index currently is 8.000% per annum.  The interest rate to be applied to the
unpaid principal balance of this Note will be at a rate of 1.250 percentage
points over the Index, resulting in an initial rate of 9.250% per annum.
NOTICE:  Under no circumstances will the interest rate on this Note be more
than the maximum rate allowed by applicable law.

PREPAYMENT:  Borrower may pay without penalty all or a portion of the amount
owned earlier than it is due.  Early payments will not, unless agreed to by
Lender in writing, relieve Borrower or Borrower's obligation to continue to
make payments of accrued unpaid interest.  Rather, early payments will reduce
the principal balance due.  Borrower agrees not to send Lender payments
marked "paid in full," "without recourse," or similar language.  If Borrower
sends such a payment, Lender may accept it without losing any of Lender's
rights under this Note, and Borrower will remain obligated to pay any further
amount owed to Lender.  All written communications concerning disputed
amounts, including any check or other payment instrument that indicates that
the payment constitutes "payment in full" of the amount owned or that is
tendered with other

<PAGE>

                                                                          Page 2
                                PROMISSORY NOTE
                                  (CONTINUED)

================================================================================
conditions or limitations or as full satisfaction of a disputed amount must
be mailed or delivered to: Tulsa National Bank, 7120 S. Lewis, P.O. Box 1051,
Tulsa, OK 74136.

INTEREST AFTER DEFAULT:  Upon default, including failure to pay upon final
maturity, Lender, at its option, may, if permitted under applicable law,
increase the variable interest rate on this Note to 21.000% per annum.  The
interest rate will not exceed the maximum rate permitted by applicable law.

DEFAULT:  Each of the following shall constitute an event of default ("Event
of Default") under this Note:

          Payment Default.  Borrower fails to make any payment when due under
          this Note.

          Other Defaults.  Borrower fails to comply with or to perform any other
          term, obligations, covenant or condition contained in this Note or in
          any of the related documents or to comply with or to perform any term,
          obligation, covenant or condition contained in any other agreement
          between Lender and Borrower.

          False Statements.  Any warranty, representation or statement  made or
          furnished to Lender by Borrower or on Borrower's behalf under this
          Note or the related documents is false or misleading in any material
          respect, either now or at the time made or furnished or becomes false
          or misleading at any time thereafter.

          Insolvency.  The dissolution or termination of Borrower's existence as
          a going business, the insolvency of Borrower, the appointment of a
          receiver for any part of Borrower's property, any assignment for the
          benefit of creditors, any type of creditor workout, or the
          commencement of any proceeding under any bankruptcy or insolvency laws
          by or against Borrower.

          Creditor or Forfeiture Proceedings.  Commencement of foreclosure or
          forfeiture proceedings, whether by judicial proceeding, self-help,
          repossession or any other method, by any creditor of Borrower or by
          any governmental agency against any collateral securing the loan. This
          includes a garnishment of any of Borrower's accounts, including
          deposit accounts, with Lender. However, this Event of Default shall
          not apply if there is a good faith dispute by Borrower as to the
          validity or reasonableness of the claim which is the basis of the
          creditor or forfeiture proceeding and if Borrower gives Lender written
          notice of the creditor or forfeiture proceeding and deposits with
          Lender monies or a surety bond for the creditor or forfeiture
          proceeding, in an amount determined by Lender, in its sole discretion,
          as being an adequate reserve or bond for the dispute.

          Events Affecting Guarantor.  Any of the preceding events occurs with
          respect to any Guarantor of any of the indebtedness or any Guarantor
          dies, or becomes incompetent, or revokes or disputes the validity of,
          or liability under, any guaranty of the indebtedness.

          Change in Ownership.  Any change in ownership of twenty-five percent
          (25%) or  more of the common stock of Borrower.

          Adverse Change.  A material adverse change occurs in Borrower's
          financial condition, or Lender believes the prospect of payment or
          performance of this Note is impaired.

          Insecurity.  Lender in good faith believes itself insecure.

LENDER'S RIGHTS.  Upon default, Lender may declare the entire principal
balance on this Note and all accrued unpaid interest immediately due, and
then Borrower will pay that amount.

ATTORNEYS' FEES; EXPENSES.  Lender may hire or pay someone else to help
collect the loan if Borrower does not pay.  Borrower also will pay Lender
that amount.  This includes, subject to any limits under applicable law,
Lender's attorneys' fees and Lender's legal expenses, whether or not there is a

<PAGE>

                                                                          Page 3
                                PROMISSORY NOTE
                                  (CONTINUED)

================================================================================
lawsuit, including without limitation all attorneys' fees and legal
expenses for bankruptcy proceedings (including efforts to modify or vacate
any automatic stay or injunction), and appeals.  If not prohibited by
applicable law, Borrower also will pay any court costs, in addition to all
other sums provided by law.

GOVERNING LAW.  This Note will be governed by, construed and enforced in
accordance with federal law and the laws of the State of Oklahoma.  This Note
has been accepted by Lender in the State of Oklahoma.

RIGHT OF SETOFF.  Borrower grants to Lender a contractual security interest
in all Borrower's accounts with Lender (whether checking, savings, or some
other account). This includes all accounts Borrower holds jointly with
someone else and all accounts Borrower may open in the future.  However, this
does not include any IRA or Keogh accounts, or any trust accounts for which
the grant of a security interest would be prohibited by law.  Borrower
authorizes Lender, to the extent permitted by applicable law, to charge or
setoff all sums owing on the indebtedness against any and all such accounts,
and, at Lender's option, to administratively freeze all such accounts to
allow Lender to protect Lender's charge and setoff rights provided in this
paragraph.

LINE OF CREDIT.  This Note evidences a revolving line of credit.  Advances
under this Note, as well as directions for payment from Borrower's accounts,
may be requested orally or in writing by Borrower or by au authorized person.
 Lender may, but need not, require that all oral requests be confirmed in
writing.  Borrower agrees to be liable for all sums either: (A) advanced in
accordance with the instructions of an authorized person or (B) credited to
any of Borrower's accounts with Lender.  The unpaid principal balance owing
on this Note at any time may be evidenced by endorsements on this Note or by
Lender's internal records, including daily computer printouts.  Lender will
have no obligation to advance funds under this Note if: (A) Borrower or any
guarantor is in default under the terms of this Note or any agreement that
Borrower or any guarantor has with Lender, including any agreement made in
connection with the signing of this Note; (B) Borrower or any guarantor
ceases doing business or is insolvent; (C) any guarantor seeks, claims or
otherwise attempts to limit, modify or revoke such guarantor's guarantee of
this Note or any other loan with Lender; (D) Borrower has applied funds
provided pursuant to this Note for purposes other than those authorized by
Lender; or (E) Lender in good faith believes itself insecure.

GENERAL PROVISIONS.  Lender may delay or forgo enforcing any of its rights or
remedies under this Note without losing them.  Borrower and any other person
who signs, guarantees or endorses this Note, to the extent allowed by law,
waive presentment, demand for payment, and notice of dishonor.  Upon any
change in the terms of this Note, and unless otherwise expressly stated in
writing, no party who signs this Note, whether as maker, guarantor,
accommodation maker or endorser, shall be released from liability.  All such
parties agree that Lender may renew or extend (repeatedly and for any length
of time) this loan or release any party or guarantor or collateral; or
impair, fail to realize upon or perfect Lender's security interest in the
collateral; and take any other action deemed necessary by Lender without the
consent or of notice to anyone.  All such parties also agree that Lender may
modify this loan without the consent of or notice to anyone other than the
party with whom the modification is made.  The obligations under this Note
are joint and several.

PRIOR TO SIGNING THIS NOTE, BORROWER READ AND UNDERSTOOD ALL THE PROVISIONS
OF THIS NOTE, INCLUDING THE VARIABLE INTERSET RATE PROVISIONS. BORROWER
AGREES TO THE TERMS OF THE NOTE.

<PAGE>

                                                                          Page 4
                                PROMISSORY NOTE
                                  (CONTINUED)

================================================================================
BORROWER ACKNOWLEDGES RECEIPT OF A COMPLETED COPY OF THIS PROMISSORY NOTE.


BORROWER:


HEARTSOFT SOFTWARE COMPANY

By:  /s/ Benjamin P. Shell                  By:  /s/ Jimmy Butler
     --------------------------------            -------------------------------
     Benjamin P. Shell, Chairman of              Jimmy Butler, Vice President of
     Heartsoft Software Company                  Heartsoft Software Company