Alert popup in php

[Chad Ryan]

Hi,
I'm doing a registration form wherein I want to popup a message if a username is already taken. But I have failed and I don't know anymore.

To start, I have 2 files, registration.html where the form is, and query_register.php where the php code for querying the submitted form is.
Here's the php code in query_register.php where I want to popup an alert message that username is already taken.
<?php
...
...
if($count >= 1) { //if username exists in database
header('Location: registration.html');
echo'<script type="text/javascript"> alert(\'Hi\'); </script>';
}
...
...
?>

but it does not work..please help...

[Dormilich]

as a side note. a JavaScript popup is done on the client, while PHP is done on the server. so you can’t do a popup in PHP.