Integrating Paypal With Custom Payment Form

Hello Everyone,

I'm having a bit of a problem integrating a Paypal "Pay Now button in my custom payment form. Th form has 2 drop down list, one prompts the users to choose their price and the other ask them to choose the product. How can I get the Paypal button to acknowledge the amount and item the user chooses?


Sorry if I didn't explain it well enough.

Thanks, any advice is appreciated.