<img alt="aaa">当mouseover时提示很慢，怎样才能立即显示？

Question

<img src="http://lucky.myrice.com/back.jpg" width=200 onmouseout="m.style.visibility='hidden';" onmousemove="m.style.visibility='visible';m.style.top=event.clientY+15;m.style.left=event.clientX+15;">
<div id=m style="position:absolute;top:0;left:0;visibility:hidden;width:50;background-color:#0099FF">aaa</div>

Answer 1

<script>
function hideAlt(oThis)
{
yourAlt.style.display = "none";
}
function displayAlt(oThis)
{
if (oThis.alt)
{
oThis.tag=oThis.alt;
oThis.alt="";
}
yourAlt.style.top  = oThis.offsetTop + event.offsetX;
yourAlt.style.left = oThis.offsetLeft + event.offsetY;
yourAlt.style.display = "block";
yourAlt.innerText = oThis.tag;

}
</script>
<div id=yourAlt style="position:absolute;display:none;background-Color:infobackground"></div>
<img alt="aaa" onmouseover="displayAlt(this)" onmouseout="hideAlt(this)">

Answer 2

假如我想yourAlt适用于所有的有alt或title属性的标记怎样，
每个标记都onmouseover和onmouseout不方便。