Session variables ... login name/password

[KiwiDexter]

I am checking if someone is logged in on my index.php form, if it is the first time accessing the form it throws an error.

Is it correct to check for session variables via the ISSET() function or is there a better way, sorry don't have code on this here PC.

[penagate]

Yes, you can use session_start followed by isset($_SESSION['token']), where 'token' is set upon login.