各位兄弟问一下，我怎样才能动态显示一个层!

test.htm<script src="poptext.js"></script>
<table>
<tr><td  title="灰豆宝宝.net">wanghr100</td></tr>
<tr><td  title="灰豆大仙.net">wanghr100</td></tr>
</table>poptext.js//***********默认设置定义.*********************
tPopWait=50;//停留tWait豪秒后显示提示。
tPopShow=5000;//显示tShow豪秒后关闭提示
showPopStep=20;
popOpacity=70;//***************内部变量定义*****************
sPop=null;
curShow=null;
tFadeOut=null;
tFadeIn=null;
tFadeWaiting=null;document.write("<style type='text/css'id='defaultPopStyle'>");
document.write(".cPopText {  background-color: #F8F8F5;color:#000000; border: 1px #000000 solid;font-color: font-size: 12px; padding-right: 4px; padding-left: 4px; height: 20px; padding-top: 2px; padding-bottom: 2px; filter: Alpha(Opacity=0)}");
document.write("</style>");
document.write("<div id='dypopLayer' style='position:absolute;z-index:1000;' class='cPopText'></div>");
function showPopupText(){
var o=event.srcElement;
MouseX=event.x;
MouseY=event.y;
if(o.alt!=null && o.alt!=""){o.dypop=o.alt;o.alt=""};
        if(o.title!=null && o.title!=""){o.dypop=o.title;o.title=""};
if(o.dypop!=sPop) {
sPop=o.dypop;
clearTimeout(curShow);
clearTimeout(tFadeOut);
clearTimeout(tFadeIn);
clearTimeout(tFadeWaiting);
if(sPop==null || sPop=="") {
dypopLayer.innerHTML="";
dypopLayer.style.filter="Alpha()";
dypopLayer.filters.Alpha.opacity=0;
}
else {
if(o.dyclass!=null) popStyle=o.dyclass 
else popStyle="cPopText";
curShow=setTimeout("showIt()",tPopWait);
}

}
}function showIt(){
dypopLayer.className=popStyle;
dypopLayer.innerHTML=sPop;
popWidth=dypopLayer.clientWidth;
popHeight=dypopLayer.clientHeight;
if(MouseX+12+popWidth>document.body.clientWidth) popLeftAdjust=-popWidth-24
else popLeftAdjust=0;
if(MouseY+12+popHeight>document.body.clientHeight) popTopAdjust=-popHeight-24
else popTopAdjust=0;
dypopLayer.style.left=MouseX+12+document.body.scrollLeft+popLeftAdjust;
dypopLayer.style.top=MouseY+12+document.body.scrollTop+popTopAdjust;
dypopLayer.style.filter="Alpha(Opacity=0)";
fadeOut();
}function fadeOut(){
if(dypopLayer.filters.Alpha.opacity<popOpacity) {
dypopLayer.filters.Alpha.opacity+=showPopStep;
tFadeOut=setTimeout("fadeOut()",1);
}
else {
dypopLayer.filters.Alpha.opacity=popOpacity;
tFadeWaiting=setTimeout("fadeIn()",tPopShow);
}
}function fadeIn(){
if(dypopLayer.filters.Alpha.opacity>0) {
dypopLayer.filters.Alpha.opacity-=1;
tFadeIn=setTimeout("fadeIn()",1);
}
}
document.onmouseover=showPopupText;