Javascript alert and php header

Question

I got a little problem. When I got my PHP script without header it\'s fine, I am getting javascript alert box. But when I use header before alert it\'s not working. It\'s re

Answer 1

I know this is a old post, but here is how I made it in a similar example. This example checks if the administrator has logged in from a specific IP address, if it returns false it should redirect the user back to the login page and show an error message.

User has logged in page:

if ($_SERVER['REMOTE_ADDR'] == "ip address"){
    $admin = True;
}else{
    session_start();
    $_SESSION['errorMessage'] = "WARNING: You dont have access to this area.";
    header("Location: login.php");
}

login.php:

session_start();

if(isset($_SESSION['errorMessage'])){
    echo "<script type='text/javascript'>
            alert('" . $_SESSION['errorMessage'] . "');
          </script>";
    //to not make the error message appear again after refresh:
    session_unset($_SESSION['errorMessage']);
}