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 >