User changing something on a form makes asp.net take user to login page

[Raj]

Hi,
I have an application that displays the database table records on
the web page, the user can navigate thru the contents and make changes
and update the database. ( one record after the other )

I have given a textbox where in they can jump to anyrecord in the
table. Everything was working fine till I introduced login page into
the application. The users are now able to go back and forth using
navigation buttons.

But, when they enter a particular number of record they want to go
to, the application takes them to the login page. I dont know what is
happening. I am under the assumption that the authentication cookie is
lost. Does anyone have any suggestion.

TIA
Raj