New to passing session through variable, Having problem..

[Timsoft]

I am trying to use an authentication script to verify username and password, and then store other fields from the record set in a session variable. If the authentication is successful, the page redirects to main.php.

The page is redirecting, but the session variable doesn't seem to be passing.

Here is the code.

<?php 
header('Location: main.php');
session_start();

//Connect to DB
$username = "xxxxxxx";
$password = "xxxxxxxx";
$hostname = "xxxxxxxxxxx";

$dbh = mysql_connect($hostname, $username, $password) 
	or die("Unable to connect to MySQL");
	if (!$dbh)
  {
  die('Could not connect: ' . mysql_error());
  }


// Verify username and ppassword are entered, then convert them to variables
if (isset($_POST['username']) && isset($_POST['password'])) 


   $userId = $_POST['username'];
   $password = $_POST['password'];


   // check if the user id and password combination exist in database

   mysql_query("USE Tpowell04");

   $sql = "SELECT * 
           FROM `6944`
           WHERE username = '$userId' 
                 AND password =  '$password'";

   mysql_query($sql) 
             or die('Query failed. ' . mysql_error()); 


  //Return Results, place array in session variable
  $result = mysql_query($sql) or die(mysql_error()); 


  $row = mysql_fetch_assoc($result) or die(mysql_error()); 

  $_SESSION['user'] = $row;

  header('Location: main.php');


 // Redirect to main page
  header('Location: main.php');

  exit;




?>

Then, I'm trying to use this simple script to verify that the variable has been transfered to the redirect page.

 <?php 
			  $userid = $_SESSION['user']['user_id']; 
			  echo Welcome, "$userid"; ?>

[NogDog]

 <?php
              [color=red]session_start();[/color]
              $userid = $_SESSION['user']['user_id'];
              echo Welcome, "$userid"; ?> 

[bradgrafelman]

In other words, you must call [man]session_start/man on every page you wish to use session data.

Also, if that doesn't work, try adding a [man]session_write_close/man on the first page after you're done modifying session data, just in case it's not finished writing data by the time the browser makes another request.