登录失败不显示

Question

I have a login form that will give an error if the username and password is incorrect and display index.php if its successful. Now the successful login works fine. But the message if there is an error is not appearing. Just shows a blank page.

P.S. How would i force a page to go through the login page before accessing it?

My connectivity.php code:

<?php 
define('DB_HOST', 'localhost'); 
define('DB_NAME', 'list'); 
define('DB_USER','root'); 
define('DB_PASSWORD','****');

$con=mysql_connect(DB_HOST,DB_USER,DB_PASSWORD) or die("Failed to connect to MySQL: " . mysql_error()); 
$db=mysql_select_db(DB_NAME,$con) or die("Failed to connect to MySQL: " . mysql_error()); 
/* 
$ID = $_POST['user']; 
$Password = $_POST['pass']; 
*/
function SignIn() 
{ 
    session_start(); 
    if(!empty($_POST['user'])) 
    { 
        $query = mysql_query("SELECT * FROM UserName where userName = '$_POST[user]' AND pass = '$_POST[pass]'") or die(mysql_error()); 
        $row = mysql_fetch_array($query) or die(mysql_error()); 
        if(!empty($row['userName']) AND !empty($row['pass'])) 
        { 
            $_SESSION['userName'] = $row['pass']; 
            header("Location: index.php");

        } 

        else 
        {
            echo "SORRY... YOU ENTERD WRONG ID AND PASSWORD... PLEASE RETRY...";
        } 
    }  

}
if(isset($_POST['submit'])) 

{ 
    SignIn(); 
} 
?>

Answer 1

I have fixed the issue. in the line:

$row = mysql_fetch_array($query) or die(mysql_error()); 

I removed the "or die" part of the code because when the username or password is wrong the $row has nothing to show so it terminates and doesn't get a chance to go to the the else statement.

Code is working now! Thank you everyone