customize wordpress database error page

This works fine for me as db-error.php in wp-content:

Delete the mailer block if you don’t want it

<?php header('HTTP/1.1 503 Service Temporarily Unavailable'); ?>

<?php 
$to = "[email protected]"; 
$subject = "My Database is down"; 
$message = "My Database is down"; 
$headers = "MIME-Version: 1.0\n"; 
$headers .= "Content-type: text/plain; charset=iso-8859-1\n"; 
$headers .= "X-Mailer: php\n"; 
$headers .= "From: \"Admin\" <[email protected]>\n"; 
mail($to,$subject,$message,$headers); 
?> 


<!DOCTYPE HTML>
<html dir="ltr" lang="en-US">
    <head>
<meta http-equiv="content-type" content="text/html; charset=utf-8">
        <title>503 Service Temporarily Unavailable</title>
        <style type="text/css">
            h1, p {
                font-family: Helvetica, sans-serif;
                font-size: 26px;
                color: #333;
                }
            p {
                font-size: 16px;
                }
        </style>
    </head>
    <body>


   <center>
            <h1>My Site is taking a nap right now....</h1>
        <p>But really, we're currently experiencing technical issues &mdash; Please check back soon....</p>
   </center>
    </body>
</html>