session code not working

[this.user]

I have this code, that determines if the user has a session running, if not checks for a cookie and if they have cookie create a session for them if not, send them to the index page.

 

However, it does not work. It does not send the user back to the index page when appropriate.

 

Can someone please tell me whats wrong i have no clue.

 

<?php session_start();
$sessionuser = $_SESSION['user'];
$sessionpassword = $_SESSION['password'];
$ui = "";
$sessionquery = "SELECT id FROM user WHERE username = '" . trim($sessionuser) . "' AND password = '" . trim($sessionpassword) ."'";
$query_sessionresult = mysql_query($sessionquery) or die(mysql_error());
if (mysql_num_rows($query_sessionresult) == 0)
{
  	if(isset($_COOKIE['user'])&&(isset($_COOKIE['password'])))
	{
		$cookieuser = mysql_real_escape_string($_COOKIE['user']);
		$cookiepassword = mysql_real_escape_string($_COOKIE['password']);
		$cookiequery = "SELECT id FROM user WHERE username = '$cookieuser' AND password = '$cookiepassword'";
		$query_cookieresult = mysql_query($cookiequery) or die(mysql_error());
		if(mysql_num_rows($query_cookieresult) == 0)
		{
			header("Location: index.php");
			die();
		}
		else
		{
			$query_cookierow = mysql_fetch_array($query_cookieresult);
			$ui = $query_cookierow['id'];
		}
	}
	else
	{
		header("Location: index.php");
		die();
	}
}
else
{
	$query_sessionrow = mysql_fetch_array($query_sessionresult);
	$ui = $query_sessionrow['id'];
}?>

[this.user]

bump

[phpretard]

When I run into session problems I always start with the basics and make sure the correct session isset:

 

<? 

echo "<pre>". print_r($_SESSION,true) ."</pre>"; 

echo "<pre>". print_r($_COOKIE)."</pre>"; 

?>