the page is not redirecting because the there is a blank spacee at the end of the code I had you add:
"<?php if(!session_id()) session_start(); ?> "
remove the blank space from the end of line 1 fix the redirect problem:
"<?php if(!session_id()) session_start(); ?>"
to troubleshoot the update further, add the following code after the <body> tag:
<pre><?php var_dump($_SESSION); ?></pre>
This will write the contents of the session array to the screen to help me see what is going wrong.
Please post back the session information that is written to the screen.