Custom Registration Page

I’m trying to build a registration page similar to that of Gmail’s (as an example). To do this I am attempting to follow the example #2 given in the codex page “Plugin API/Action Reference/register form” but I cannot get it to work.

I have created a file called “regpager.php” (code below) in my site’s plug-in directory and then activate it via the dashboard but when I access http://mysite.com/wp-login.php?action=register I see no change.

<?php
/*
Plugin Name: Registration Page Changer
Description: This is just a test plugin.
Author: Mike B
Version: 0.1
Author URI: http://mi.ke/
*/

function my_translate()
{
   $your_content=ob_get_contents();
   $your_content= preg_replace('/\<label for="user_login"\>(.*?)\<br/',        'Usernumia: ',$content);
   $your_content= preg_replace('/\<label for="user_email"\>(.*?)\<br/',        'Email Sior:',$content);

   ob_get_clean();
   echo $your_content;
}
add_action( 'register_form', 'my_translate' );

?>

Any help you guys are able to offer would be super appreciated 🙂

Thanks everyone.