//顶部伸展广告
$(document).ready(function () {
    if ($("#js_ads_banner_top_slide").length) {
        var $slidebannertop = $("#js_ads_banner_top_slide"), $bannertop = $("#js_ads_banner_top");
        setTimeout(function () { $bannertop.slideUp(1000); $slidebannertop.slideDown(1000); }, 2500);
        setTimeout(function () { $slidebannertop.slideUp(1000, function () { $bannertop.slideDown(1000); }); }, 8500);
    } 
});