js弹出窗口自适应大小

  //弹出窗口高度调整自适应 
  function resetDialogHeight(){
   if(window.dialogArguments == null){
    return; //忽略非模态窗口
   }
   //正文高度
   var height = document.body.scrollHeight;
   //卷进去高度
   var heightTop = document.body.scrollTop;
   if (window.XMLHttpRequest) {
    window.dialogHeight=(height+heightTop+5)+"px";
   } else {
    window.dialogHeight=(height+heightTop+55)+"px";//IE6不能自动调整高度，要加45
   }
  }
  window.attachEvent('onload', function(){resetDialogHeight();});