Problem with $PHP_SELF on PWS

Hello All, I have PHP installed on PWS running on a Windows 98SE m/c. When I invoke <form action="action.php" method="POST"> everything is fine and the form data is extracted correctly. When I try to embed the same script in the body of the form using <form action="<?php $PHP_SELF; ?>" method="POST"> I get "HTTP Error 405 Method not allowed. The method specified in the request line is not allowed for the resource identified by the request. Please ensure that you have the proper MIME type set up for the resource you are requesting." I'm sorry if this is a "newbie" problem, but I can't for the life of me see what the difference is between having the method embedded or separate. Thanks in advance, John Brooks.