lesP> If you really want some help solving this, post your login script code, at least the bit that pertains to setting any session data.
A good method to troubleshoot has already been suggested by
Alan@CIT. At the top of each script you're accessing the session, do this
PHP Code:
<?php
session_start();
print_r($_SESSION);
...
This will leave no doubt as to what session data is set. You may want to just create a separate test script to do nothing but check session data, as I've done many times.
The best advice I can give you, start in small increments while developing an application. Don't just throw a bunch of code together and hope the session or POST data gets through. Create your interface, then build the code to process it. Start with a script that does nothing but receive the data and let you view what's coming through. Once you're confident that the data is there, the next step is to validate, filter, check, escape etc ad nauseum. After all this is done, create the SQL and eventually finish with fine tuning the script logic.
HTH