原理很简单，就是浮动 position:absolute,可关闭

  //轻量级jquery对联广告插件  //版权 优装网 www.youzhuang.net  //作者 逐月 zhuyue.cnblogs.com  //演示 http://www.youzhuang.net  //调用方法  //$("body").couplet({width:100,height:300,leftCouplet:"http://www.youzhuang.net/ad/left.swf",rightCouplet:"http://www.youzhuang.net/ad/right.swf"});});  //调用参数  //width:100,--宽 默认宽度100  //height:300,--总高 默认高度 300  //top:100,广告距顶部的高度  //leftCouplet:"http://www.youzhuang.net/ad/left.swf",左则flash地址或图片地址  //leftLink:"http://www.youzhuang.net/",左则连接地址，广告是图片时需要  //rightCouplet:"http://www.youzhuang.net/ad/right.swf",右则flash地址或图片地址  //rightLink:"http://www.youzhuang.net/"右则连接地址，广告是图片时需要    jQuery.fn.couplet = function(settings) {                               settings = jQuery.extend({                  width: 100,                  height:300,                  top:100,                  leftCouplet:"",                  leftLink:"http://www.youzhuang.net/",                  rightCouplet:"",                  rightLink:"http://www.youzhuang.net/"              },              settings);              var s = this;              //添加广告窗口             s.append("<div class=\"couplet\" id=\"leftCouplet\" style=\"width:"+settings.width+";left:10px;top:0px; position:absolute;background:#e5e5e5;\"></div>");             s.append("<div class=\"couplet\" id=\"rightCouplet\" style=\"width:"+settings.width+";right:10px;top:0px; position:absolute;background:#e5e5e5;\"></div>");             var leftCouplet = s.children("#leftCouplet");             var rightCouplet = s.children("#rightCouplet");             //加载左则广告             if(settings.leftCouplet.substring(settings.leftCouplet.lastIndexOf('.')).toLowerCase() == ".swf"){                  leftCouplet.append("<div><embed src=\""+settings.leftCouplet+"\" width=\""+settings.width+"\" height=\""+settings.height+"\" </embed></div>");             }else{                  leftCouplet.append("<a href='"+settings.leftLink+"' target='_blank'><img src=\""+settings.leftCouplet+"\" width=\""+settings.width+"\"  height=\""+settings.height+"\"/></a>");             }             //加载右则广告             if(settings.rightCouplet.substring(settings.rightCouplet.lastIndexOf('.')).toLowerCase() == ".swf"){                  rightCouplet.append("<embed src=\""+settings.rightCouplet+"\" width=\""+settings.width+"\" height=\""+settings.height+"\" frameborder=\"0\"></embed>");             }else{                  rightCouplet.append("<a href='"+settings.rightLink+"' target='_blank'><img src=\""+settings.rightCouplet+"\" width=\""+settings.width+"\"  height=\""+settings.height+"\"/></a>");             }             var closeBtn = "<div class=\"coupletClose\" style=\"text-align:center;padding:2px 0px;font-size:12px;cursor:pointer \">关闭</label>";             leftCouplet.append(closeBtn);             rightCouplet.append(closeBtn);             $(".coupletClose").click(function(){                 leftCouplet.remove();                  rightCouplet.remove();              });               //显示对联              show();                            function show(){                  var winTop = $(window).scrollTop();                  $(".couplet").animate({                     top: winTop + settings.top                   }, 300);                              };              //滚动条事件              $(window).scroll(function() {                   $(".couplet").stop();                  show();              });                      };