(function($) {
    $.fn.couplets = function(o) {

        o = $.extend({
            top: 60,  //广告距页面顶部距离
            left: 0, //广告左侧距离
            right: 0, //广告右侧距离
            width: 100,  //广告容器的宽度
            height: 360, //广告容器的高度
            minScreenW: 800, //出现广告的最小屏幕宽度，当屏幕分辨率小于此，将不出现对联广告
            position: "left", //对联广告的位置left-在左侧出现,right-在右侧出现
            allowClose: true //是否允许关闭 
        }, o || {});
        var h = o.height;
        var showAd = true;
        var fDiv = $(this);
        if (o.minScreenW >= $(window).width()) {
            fDiv.hide();
            showAd = false;
        }
        else {
            fDiv.css("display", "block")
            var closeHtml = '<div align="right" style="padding:2px;z-index:2000;font-size:12px;cursor:pointer;border-bottom:1px solid #f1f1f1; height:20px;" class="closeFloat"><img src="/images/delete.gif" alt="关闭"/></div>';
            switch (o.position) {
                case "left":
                    if (o.allowClose) {
                        fDiv.prepend(closeHtml);
                        $(".closeFloat", fDiv).click(function() { $(this).hide(); fDiv.hide(); showAd = false; })
                        h += 20;
                    }
                    fDiv.css({ position: "absolute", left: o.left + "px", top: o.top + "px", width: o.width + "px", height: h + "px", overflow: "hidden" });
                    break;
                case "right":
                    if (o.allowClose) {
                        fDiv.prepend(closeHtml)
                        $(".closeFloat", fDiv).click(function() { $(this).hide(); fDiv.hide(); showAd = false; })
                        h += 20;
                    }
                    fDiv.css({ position: "absolute", left: "auto", right: o.right + "px", top: o.top + "px", width: o.width + "px", height: h + "px", overflow: "hidden" });
                    break;
            };
        };
        function floatCouplets() {
            if (!showAd) { return }
            var windowTop = $(window).scrollTop();
            if (fDiv.css("display") != "none")
                fDiv.css("top", o.top + windowTop + "px");
        };

        $(window).scroll(floatCouplets);
        $(document).ready(floatCouplets);

    };
})(jQuery);