Not sure of your set-up but from what I read it sounds like you should consider using a scripting language to do the form processing locally.

For example, javascript is widely used in this siutation.

By doing the processing *locally* it saves the time otherwise required to

• send duff data to the server
• process it remotely
• return results
• re-write page

Using the "onSubmit()" attribute associated with <FORM>, and with a local scripting language it's a doddle to do the data validation, alert the user to the error(s) and avoid submitting the form.