Best way to redirect a .net domain to a .com

[Verbal]

When I get a good .com domain I like to also pick up the .net version, but I usually don't put anything on there. What is the proper (and SEO friendly) way to foward someone from blah.net to blah.com?

Currently I just do it by putting this on index.php:

PHP Code:

<?php
header("Location: http://www.blah.com/"); /* Redirect browser */

/* Make sure that code below does not get executed when we redirect. */
exit;
?>