javascript:window.external.AddFavorite('http://www.yoursitename.com/','Your Site Title') ;
You can edit the italicized sections to reflect your site URL and name, and copy-paste that directly into the URL field to complete the getURL functions parameters. When its finished, it should appear similar to this:
on (release) {
getURL("javascript:window.external.AddFavorite('http://animation.about.com/','Animation@About.com') ;") ;
}

