Untitled

<?php
//Authentication Script, log a user in or out of the system
//Include required functions
require_once('sessionfunc.php');

//Create shorter names for variables
@$username= $_POST['username'];
@$passwd= $_POST['passwd'];

//Clear errorcode variable if it already exists
if(isset($_GET['errcode']))
{ unset($_GET['errcode']); }

session_start();

//Execute for login
if ($_POST['action']=="Login")
{
//Check if either field is empty
 if ((empty($username)) || (empty($passwd)))
  {
  $url= $_SESSION['pageurl']."?errcode=1";
  header('Location:' . $url);
  }
 else
 {
 //Connect to the database
 $handle = dbhandle();
 //cannot use dberror as not using $result
  if (!$handle)
   {
   $url= $_SESSION['pageurl']."?errcode=6";
   header('Location:' . $url);
   exit;
   }//otherwise connect to database
  else {$connect = mysql_select_db('a7464386_justbe', $handle);}

  //Check if provided username and password match

  $result = mysql_query("SELECT * FROM user WHERE username= '$username' AND passwd = PASSWORD('$passwd')");
  //Check for database error
  dberror($result);

 //If result is found, true otherwise username or password is wrong
  if (mysql_num_rows($result)>0)
   {
   $_SESSION['validuser'] = $username;
   $url = $_SESSION['pageurl'];
   header('Location:' . $url);
   exit;
   }
  else
   {
   $url = $_SESSION['pageurl']."?errcode=12";
   header('Location:' . $url);
   exit;
   }
 }
 }

//Execute for logout
else
{
//No longer passes as logged in but rest of session data can remain until expiry
unset($_SESSION['validuser']);
$url = $_SESSION['pageurl'];
echo $url;
header('Location:' . $url);
exit;
}
?>