Form Re-Sending On Header Change

[DeanWhitehouse]

<?php
require_once '../includes/main.inc.php';
require_once '../includes/db_connect.php';
require_once '../includes/config_table.inc.php';
session_start();



// Only include the header and footers if you have to print errors
function print_error($err_message)
{
require_once '../includes/header.php';
require_once '../includes/footer.php';
require_once '../nav_bar.php';
echo $err_message;
exit;
}

$user_name = $_POST["user_name"];        
$user_password = $_POST["user_password"];    
$verify_username = strlen($user_name);
$verify_pass = strlen($user_password);
if ($verify_pass > 0 && $verify_username > 0)
{
$salt = substr($user_password, 0, 2);
$userPswd = crypt($user_password, $salt);
$sql = "SELECT * FROM `$user` WHERE user_name='$user_name' AND user_password='$userPswd' LIMIT 1;";
$result = mysql_query($sql);
if (mysql_num_rows($result) == 1){
	$row = mysql_fetch_assoc($result);
	$user_level = $row['userlevel'];
	if ($user_level == 1) {
		$login_check = @mysql_fetch_array(mysql_query("SELECT * from `$user` WHERE user_name = '$_GET[u]' AND user_password = 	'$_GET[p]'"));

		$userright = array($login_check['user_name'], $login_check['userlevel']);
		$s_userpass = serialize($userpass);

		setcookie( "$cookiename" , $s_userpass , time()+$custom_time , "" , "127.0.0.1" );
		header("Location:".$_SERVER[REQUEST_URI]);
		$_SESSION['is_valid'] = true; //change the session variable name to what you want, just remember it for all files
$_SESSION['username'] = $row['user_name'];
$_SESSION['user_level'] = $row['userlevel'];

	} 
	elseif ($user_level == 2){    
		$login_check = @mysql_fetch_array(mysql_query("SELECT * from `$user` WHERE user_name = '$_GET[u]' AND user_password = '$_GET[p]'"));

		$userright = array($login_check['user_name'], $login_check['userlevel']);
		$s_userpass = serialize($userpass);

		setcookie( "$cookiename" , $s_userpass , time()+$custom_time , "" , "127.0.0.1" );
		echo "<meta http-equiv='refresh' content='0; url=../index.php'>";
		$_SESSION['is_valid'] = true; //change the session variable name to what you want, just remember it for all files
$_SESSION['username'] = $row['user_name'];
$_SESSION['user_level'] = $row['userlevel'];
	}
}
else{
	print_error( 'Login failed. Username and Password did not match database entries.');    
}
}

else
{
print_error( "Form was not completed. Please go back and make sure that the form was fully completed.");    
}


mysql_close();
?> 

this code is meant to when the admin(user level 1) logs in, redirect them to another page, but it resends the form when it gets there and says "Form was not completed. Please go back and make sure that the form was fully completed." but it does create the session and log them in, but doesn't redirect properly,any ideas?