setting up Authorize.net?

hey folks.

i am having a little trouble setting up my authorize.net account - specifically with the relay or response URL (or is it redirect URL…? - so many names that sounds all the same!).

wher do i setup the URL it must go to after processing the transaction?
and how would i get the parameters it sends? request.form or request.querystring?

thanks!

are you referring to hsphere integration?

nope, for my own application on a site.