Why is my function not working?

I’m trying to load up two JS files to just my template file ‘contact.php’. The function below isn’t working (its located in my functions.php file):

function google_map_script() {
	   // register your script location, dependencies and version
	   wp_register_script('maps_script',
	   	   'http://maps.googleapis.com/maps/api/js?sensor=false',
	       array('jquery')
	       );

	   wp_register_script('gmap_script',
	       get_template_directory_uri() . '/js/gmap.js',
	       array('jquery')
	       );

	   // enqueue the script
	   wp_enqueue_script('maps_script', 'gmap_script');
	}

	if ( is_page_template( 'contact.php' ) ) add_action('init', 'google_map_script');

I’d appreciate any pointers or help at all 🙂