submit form values to new site after validation

I'm trying to modify and e-commerce site which originally sent an email with the credit card info in an email. Now they would like to pass credit card numbers to a payment-processing service. For this particular service, Authorize.net, you would normally direct the form data to the payment-processing service. The page is currently setup to resubmit to itself and validate fields before anything else. I would like to keep that functionality but I'm wondering how to pass the values onto the payment-processing center after the validation. The flow would be, hit the submit button and send the data to the page to validate the fields and then send the info to Authorize.net. The form currently has about 15 fields to validate and only needs to pass 3 of them to the payment-processing center. I'm still relatively new to this and I'm thinking the only way to pass variables is through a submitted form or the url and I don't want to put the credit card info in the url. Any help would be greatly appreciated. Tom >>.>>.>>>.>>>>>.>>>>>>>>>.>>>>>>>> Tom Beidler Orbit Tech Services 805.682.8972 (phone) 805.682.5833 (fax) tom@orbittechservices.com http://www.orbittechservices.com/ >>.>>.>>>.>>>>>.>>>>>>>>>.>>>>>>>>