//iframe 自适应高度
         function SetCwinHeight(){
          var mainid=document.getElementById("main"); //iframe id
          if (document.getElementById){
           if (mainid && !window.opera){
                if (mainid.contentDocument && mainid.contentDocument.body.offsetHeight){
                 mainid.height = mainid.contentDocument.body.offsetHeight;
                }else if(mainid.Document && mainid.Document.body.scrollHeight){
                 mainid.height = mainid.Document.body.scrollHeight+"px";
                 
                }
           }
          }
         }