TOPIC: Deposit or Full Payment on Registration

I need to make the registration form either take a deposit, or a full amount. We are using Jevents 1.43, and joomla 1.5

ex... full class is $1899.00, but clients can leave a $500.00 deposit and reserve a spot and then pay via CC or check at the door etc...

I cannot create two registrations as the class could fill with full payers, and still be open for depositors.

Is there some way of doing this.... The only work around that I can think of is this...

Class Registration = $1899.00, but the form is only for $500.00 and then I can create a custom field for the remaining $1399.00 for full payment customers.

This would work as a ok (not really a good one) solution, but the custom fee fields do not work, and charging a late fee will not work either as this is a business right-off and late fees are not deductable (in some cases)...

Any ideas.... I really need to deliver this site in the next couple of days, and lost 2 weeks to a outside dev team, so I am working hard and fast to get this completed....

Thanks again, loved DTDONATE so I am back for DTREGISTER....