鼠标经过显示层

< html  xmlns ="http://www.w3.org/1999/xhtml"   > < head  runat ="server" >    </ head > < body >      < form  id ="form1"  runat ="server" >     问题:当绿色的DIV显示出来后,鼠标移入DIV无事,再移到aaaa正上方的一小部分局域(就aaaa四个字母上方),DIV就关了,不知为何     < div  style ="margin:0px auto 0px auto; position:absolute;left:250px;top:250px;padding:20px; z-index:1;" >             < asp:LinkButton  ID ="LinkButton1"  onmouseover ="over(this,document.all.se)"  onmouseout ="timer=setTimeout('out(document.all.se)',500)"  OnClientClick ="alert('left'+this.offsetLeft+';top'+this.offsetTop+';高'+this.offsetHeight+';宽'+this.offsetWidth);return false;"  runat ="server" > M我 </ asp:LinkButton >              </ div >                 < div  id ="se"  onmouseover ="clearTimeout(timer);this.style.display='block'"  onmouseout ="out(this)"  style =" background-color:#32ba5c; display:none; width:200px; position:absolute; padding:20px;" >                 < div  > aaaa </ div >          < div  > bbbb < input  type ="button"  onclick ="this.parentElement.parentElement.style.display='none'"  value ="关闭"   /></ div >          < div > aaaa </ div >          < div > bbbb </ div >          < div > aaaa </ div >          < div > bbbb </ div >             </ div >                   </ form > </ body > </ html > < script > ...     function over(obj,div)    ...{         var rec=getoffset(obj);         div.style.top=rec[0]+obj.offsetHeight;         div.style.left=rec[1];              div.style.display="block";            }        function out(div)    ...{        div.style.display="none";    }function getoffset(e) ...{   var t=e.offsetTop;   var l=e.offsetLeft;   while(e=e.offsetParent)  ...{    t+=e.offsetTop;    l+=e.offsetLeft;   }   var rec = new Array(1);  rec[0]  = t;  rec[1] = l;  return rec }   </ script >