Return url issue.

Question

In my application once i have logged in successfully. I have a page called as
charitycommitee.aspx in which i show comments and has a edit button.
when click on edit button the editor opens up and Text is Editable with update button
So when i click on Update button i am redirected to this url

http://ifintranet.imagefirst.net/Login.aspx?ReturnUrl=%2fCorporateCharities.aspx

basically i should be redirected to
http://ifintranet.imagefirst.net/CorporateCharities.aspx
with updated Data.

Got some issue with the Return Url.

NOTE: I am not Directing anywhere in that Page

PLease Help Its Urgent.

Thank You.