$(document).ready(function() {

    /*
     * preload images
     */
    $(window).bind('load', function() {
        var preload = [
            'images/topnav/btn-introducing-restylane-over.gif',
            'images/topnav/btn-how-it-works-over.gif',
            'images/topnav/btn-see-results-over.gif'
        ];
        $(document.createElement('img')).bind('load', function(){
            if(preload[0]) this.src = preload.shift();
        }).trigger('load');
    });

});