Hello!
am developing a site on ecommerce website (a payment solution site) it is under developing but i am in the section to write the code that other website that accept the mysite as a means of payment to their website. Please help me to make contribution and help in the analysis below..

1. I want to write a code in form of a dll or webservice that other site can download from mysite that can access mysite and validate the buyer or seller on their own site maybe the person have a valid account with mysite
2. If the person have a valid account for security purpose i want to redirect the transaction from the server to my own secure server and carry out the transaction and send back the tarnsaction message back to the other website. In short story a payment website like paypal, egold etc

Please i really endulge you to assit me find a solution to this big task of mine,
i dont care if it a referennce tutorial OR a code pls i want it using (ASP.NET)VB.NET coding


Thank for your reply