LOGOFF script-Group Policy to execute IE webpage

[Whitemtntn]

Hi--
We have a payroll system that tracks logon and logout by the users logging into a webpage.

I have the LOGON part done with our login script.
I need to write a LOGOFF script that opens a webpage as the user is logging out, giving them the opportunity to punch in their account before they leave. I've tried running iexplore

http://www.thesite.com

in a batch file, but it doesn't work.. anyone have some ideas on this?

Thanks,
Jack