Change the Login Screen Image

Normally, when you visit the login screen, there’s a nice WordPress image. If you want to change that to something else, this is how:

add_action('login_head', 'change_login_image');
function change_login_image() {
	$name = urlencode(get_option('blogname'));
	?><style type="text/css"> h1 a { background-image: url('http://dummyimage.com/310x70/f9/000&text=++<?php echo $name; ?>+'); } </style><?php
}