How can I do this in Python?

[Lad]

Hi,
I have a web program and a user can have access to a page only after he
logged in.
So, the program comes with  a Login form and the user logins.But I do
not know how to return the user back to where he came from, after a
successful login.

Something like this:

PageWhereUserMustBeLogin -------->UserSigned----->-

^------<---------------------------------------------------<----|


Thank you for help

L.