[RESOLVED] What exactly does session_start() do?

bladesedge

I have built a secured section to my website, so have used to following:

<?
session_start();
if(!session_is_registered(myusername))
{
	header("location:login.php");
}
?>
<html>

I am also using a session variable to make it easier to pass a variable from page to page (too hard to pass it through the url as the user can bounce back and forth among the pages). This is how I've declared it.

	session_register ("oid");								$oid=$_GET['oid'];

The problem I have is that on the next page it doesn't recognise $oid. Is that anything to do with session_start() at the top of every page? Does it reset the session?

bladesedge

Don't worry, fixed it myself. I was calling $oid instead of $_SESSION['oid']

Houdini

Using sessions the way you are is not really a good practice and I would advise instead using
$_SESSION['oid'] = $somevariable vice

session_register ("oid");

Just keep in mind that Session data to be assigned or read must first have session_start() invoked. To answer your original subject matter session_start() is a built in function that allows you to assign or read session data or variables and must be used to assign data or varaibles to session data or to read session data or variables.