prevent canceling of logon script

When a 95/98 client logs onto a WinNT domain and runs a logon script, if the logon script is long and the user wants to kill it…they can, just by clicking the close box on the top-right corner of the window.

How do I prevent the user from beingable to cancel out of the logon script? I want it to run completely all the time.

However I do this, it needs to be without using any third-party software.

Thanks,
Robert