session question

[SchMp]

I am having some weird problems with sessions:

The idea is very basic. I just want a very simple way to log on to a site. When you have been logged in a session variable ($_SESSION['acces']) is set to 1. You can now visited different pages while the variable still stays on 1.

When you are logged in it is possible to log out again. Once you have been logged out the $_SESSION['acces'] variable is set to 0 and it isn't possible to log out any more. The weird thing now is that when you go back to pages where you were before (when you were still logged in) you SOMETIMES get a page where you can log out again. Haven't got a clue how this is possible since the same variable has been set to 0 just earlier.

I hope someone has a logic explanation for this problem because it is driving me nuts.

Thx a lot

[halojoy]

this should
only happen when you use back button
because you get an old copy from your own computer internet history files
stored by your browser.

In such old pages, logout links can be shown, even if you are already logged out

When going Back, using back button, or using link javascript (history)
to such a previous page, you can Do a Refresh
to get a new version, with current data in SESSION(acces)
and you will see, if your script is correct,
that Link will become 'Login', in the Fresh copy of this page

There can of course be other reasons (from incorrect php checking SESSION variable in php),
but this is the most common case: old pages cached by your browser in 'history folder'

/halojoy

[SchMp]

That is the weird thing, I dont use the Back button. What just happened is that when I was logged on, and I went to the next page the $_SESSION['acces'] variable changed from 1 to 0.

It lookes like it just changes the acces value from one page to the other on a random base.

Should i maybe post some code?

[halojoy]

well, if your php script is correct
then this shouldnt happen
as long as you are logged in, and does not close down your browser
you should always be shown as logged in, and get link option=logout

otherwise you have to debug your script
and post the code that does not work correctly

and before you know it, we will have it working alright

this is no difficult problem to track, test and to fix
in case there is a session variable change problem

/halojoy

[SchMp]

I log in using this

<?
session_start();
if($_POST['name'] == "Sheep" && $_POST['pass'] == "beeh")
{
	$url = "index.php";
	$login = "login succesfull";
	$_SESSION['acces'] = 1;
}
else
{
	$url = "login.php";
	$login = "login not succesfull, try again";
}
?>

Then on every page the folowing code generates the log in/log out:

if($_SESSION['acces'] == 1)
{
	echo "<center><span class=class1><a href=logout.php>Log out</a></span></center>";
}
else
{
	echo "<center><span class=class1><a href=edit.php>Log in</a></span></center>";
}

this is basicly all I do (yes, I know it's very basic, but I just wanted a simple and fast Log in system)

And what logout.php does is

$_SESSION['acces'] = 0;

[jansky]

in your logout change that to

session_start();
session_unregister('access');
session_destroy();

[krt]

Yes, you need to start the session before changing a session variable.
You can unset/unregister the variable or destroy the session, jansky's method does both.