I have an order form on a website that when submitted, it sends all of the necessary fields to a secure shopping cart provided by my merchant account provider. The form allows the user to put in an amount that they would like to donate in exchange for a t-shirt; however, I do not want to give away a t-shirt for less than a certain donation amount.
So, what I am thinking I need to do is have the form submit action go to a php page on my server, and then if the dollar amount submitted meets the minimum, send the request on to the shopping cart. What I can't figure out how to do is set the post variables via php to be forwarded to the shopping cart.
Maybe this isn't the best solution, so if anyone has a better one, I'm open to suggestions. Otherwise, can someone tell me how to set post variables to be sent to a secure site?
