Adding Custom Post Type Icons

I need some help with getting the menu bar icon to change from the standard icon.

I have a Custom Post Type that i call “Property” and I wanted to change the icon for it.

This is the code I wrote in my posttypes.php-file.

add_action( 'admin_head', 'property_icons' );
function property_icons() {
	?>
	<style type="text/css" media="screen">
		#menu-posts-property .wp-menu-image {
			background: url(<?php bloginfo('url') ?>/wp-content/themes/images/propertysmall.png) no-repeat 6px !important;
		}
		.icon32-posts-property {
			background: url(<?php bloginfo('url') ?>/wp-content/themes/images/property.png) no-repeat !important;
		}

	</style>

The problem is that it’s only showing the big 32icon and not the 16 in the menu. What am I doing wrong?