Request variables in return url

[KBdev]

I have a simple buy now button with a few options underneath. All I need in my php or asp return page is the value of the drop down, then I can display the message that I want to. In the buy now form I have set the rm value to "2" with the return url that I want. Can I request.form the os0, os1 etc values in my return page? Do I need to also turn on IPN or PDT? Or can I leave these off? Thank you.

[Anonymous_User]

You may want to visit the Merchant Support Community as there are other developers and PayPal Techs there who may be able to help.