i am using vb.net and i dont know anything about paypal. i want paypal in my onlineeducation project.can u explain about it give code for that.whether we have to buy anything for that service.please give complete info about paypal.
thank you in advance

Be ready for hours of getting irritated too! Adatapost gave you a good start in the right direction but let me caution you -- use the projects and source code as a "non-runnable code sample." Do not waste your time trying to compile their project or using their libraries. I made this mistake and it cost me a day's worth of development to find their software was horribly busted.

The gateway works fine and their sample projects give you enough information to get the application working, but do not spend the time trying to get their applications to work.

Spicelogic has a component that you can drag-n-drop. I have used it, it's cheap and quite an efficient way to integrate PayPal into .NET apps.