Menu icons for custom post types

gistfile1.aw

<?php
add_action( 'admin_head', 'ja_custom_cpt_icons' );
function ja_custom_cpt_icons() { ?>
    <style type="text/css" media="screen">
        #menu-posts-portfolio .wp-menu-image {
            background: url(<?php echo plugin_dir_url( __FILE__ ); ?>images/portfolio-icon.png) no-repeat 6px 6px !important;
        }
		#menu-posts-portfolio:hover .wp-menu-image, #menu-posts-portfolio.wp-has-current-submenu .wp-menu-image {
            background-position:6px -16px !important;
        }
		#icon-edit.icon32-posts-portfolio {background: url(<?php echo plugin_dir_url( __FILE__ ); ?>images/portfolio-32x32.png) no-repeat;}
    </style>
<?php }