这个效果在firefox下不行

  这段代码是外面考得，效果不错，单firefox下不行。现在要用，没有前端工程师，只能赶鸭子上架了。
希望过路高手能改下，如有注释码将不甚感激，好让在下仔细研习，自此先谢过，代码如下！
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML><HEAD><TITLE>鼠标移上显示大图效果</TITLE>
<META http-equiv=Content-Type content="text/html; charset=gb2312">
<LINK href="img/css.css" type=text/css rel=stylesheet>
<style type="text/css">
<!--
body{background-image:url(image/bg-1.gif)}
.STYLE1 {LINE-HEIGHT: 20px; TEXT-DECORATION: none; font-size: 14px;}
.STYLE2 {LINE-HEIGHT: 18px; TEXT-DECORATION: none; font-size: 12px;}
-->
</style><SCRIPT language=JavaScript>
var pltsPop=null;
var pltsoffsetX = 10;
var pltsoffsetY = 15;
var pltsPopbg="#ffffee";
var pltsPopfg="#111111";
var pltsTitle="";
document.write('<div id=pltsTipLayer style="display: none;position: absolute; z-index:10001"></div>');
function pltsinits()
{
    document.onmouseover= plts;
    document.onmousemove = moveToMouseLoc;
}
function plts()
{  var o=event.srcElement;
    if(o.alt!=null && o.alt!=""){o.dypop=o.alt;o.alt=""};
    if(o.title!=null && o.title!=""){o.dypop=o.title;o.title=""};
    pltsPop=o.dypop;
    if(pltsPop!=null&&pltsPop!=""&&typeof(pltsPop)!="undefined")
    {
pltsTipLayer.style.left=-1000;
pltsTipLayer.style.display='';
var Msg=pltsPop.replace(/\n/g,"<br>");
Msg=Msg.replace(/\0x13/g,"<br>");
var re=/\{(.[^\{]*)\}/ig;
if(!re.test(Msg))pltsTitle="";
else{
  re=/\{(.[^\{]*)\}(.*)/ig;
    pltsTitle=Msg.replace(re,"$1")+"&nbsp;";
  re=/\{(.[^\{]*)\}/ig;
  Msg=Msg.replace(re,"");
  Msg=Msg.replace("<br>","");}
  var attr=(document.location.toString().toLowerCase().indexOf("list.asp")>0?"nowrap":"");
       var content =
      '<table style="FILTER:alpha(opacity=80) shadow(color=#bbbbbb,direction=150);" id=toolTipTalbe border=0><tr><td width="100%"><table class=selet_bg cellspacing="0" cellpadding="0" style="width:100%" style="font size:9pt;">'+
      '<tr id=pltsPoptop><th height=12 valign=bottom class=header><p id=topleft align=left>'+pltsTitle+'</p><p id=topright align=right style="display:none">'+pltsTitle+'?§J</font></th></tr>'+
      '<tr><td "+attr+" class=f_one style="padding-left:10px;padding-right:10px;padding-top: 4px;padding-bottom:4px;line-height:135%">'+Msg+'</td></tr>'+
      '<tr id=pltsPopbot style="display:none"><th height=12 valign=bottom class=header><p id=botleft align=left>'+pltsTitle+'</p><p id=botright align=right style="display:none">'+pltsTitle+'</font></th></tr>'+
      '</table></td></tr></table>';
       pltsTipLayer.innerHTML=content;
       toolTipTalbe.style.width=Math.min(pltsTipLayer.clientWidth,document.body.clientWidth/2.2);
       moveToMouseLoc();
       return true;
       }
    else
    {
    pltsTipLayer.innerHTML='';
      pltsTipLayer.style.display='none';
       return true;
    }
}function moveToMouseLoc()
{
if(pltsTipLayer.innerHTML=='')return true;
var MouseX=event.x;
var MouseY=event.y;
//window.status=event.y;
var popHeight=pltsTipLayer.clientHeight;
var popWidth=pltsTipLayer.clientWidth;
if(MouseY+pltsoffsetY+popHeight>document.body.clientHeight)
{
  popTopAdjust=-popHeight-pltsoffsetY*1.5;
  pltsPoptop.style.display="none";
  pltsPopbot.style.display="";
}
 else
{
   popTopAdjust=0;
  pltsPoptop.style.display="";
  pltsPopbot.style.display="none";
}
if(MouseX+pltsoffsetX+popWidth>document.body.clientWidth)
{
popLeftAdjust=-popWidth-pltsoffsetX*2;
topleft.style.display="none";
botleft.style.display="none";
topright.style.display="";
botright.style.display="";
}
else
{
popLeftAdjust=0;
topleft.style.display="";
botleft.style.display="";
topright.style.display="none";
botright.style.display="none";
}
pltsTipLayer.style.left=MouseX+pltsoffsetX+document.body.scrollLeft+popLeftAdjust;
pltsTipLayer.style.top=MouseY+pltsoffsetY+document.body.scrollTop+popTopAdjust;
  return true;
}
pltsinits();
</SCRIPT>
<META content="MSHTML 6.00.2800.1586" name=GENERATOR></HEAD>
<BODY text=#000000 bgColor=#ffffff leftMargin=0 topMargin=0>
<TABLE cellSpacing=0 cellPadding=0 width=528 
      background=img/t_2.gif border=0>
  <TBODY>
    <TR>
      <TD vAlign=top width=39>&nbsp;</TD>
      <TD><TABLE cellSpacing=0 cellPadding=3 width=470 border=0>
        <TBODY>
          <TR>
            <TD colspan="3">&nbsp;</TD>
          </TR>
          <TR class="content02">
            <TD align="center" bgColor=#ffffff><a href="bgimg/cps800bg01.jpg" target="_blank"><img src="bgimg/smalcps800bg01.jpg" alt="&lt;img border='0'  width='400' height='223' src='bgimg/cps800bg01.jpg'&gt;" width="151" height="84" border="0"></a><br>
              主题1</TD>
            <TD align="center" bgColor=#ffffff><a href="bgimg/cps800bg02.jpg" target="_blank"><img src="bgimg/smalcps800bg02.jpg" alt="&lt;img border='0'  width='400' height='223' src='bgimg/cps800bg02.jpg'&gt;" width="151" height="84" border="0"></a><br>
              主题2</TD>
            <TD align="center" bgColor=#ffffff><a href="bgimg/cps800bg03.jpg" target="_blank"><img src="bgimg/smalcps800bg03.jpg" alt="&lt;img border='0'  width='400' height='223' src='bgimg/cps800bg03.jpg'&gt;" width="151" height="84" border="0"></a><br>
              主题3</TD>
          </TR>
        </TBODY>
      </TABLE>
          <TABLE cellSpacing=0 cellPadding=3 width=470 border=0>
            <TBODY>
              <TR>
                <TD colspan="3"><DIV align=center><IMG height=5 src="img/blank.gif" width=30><br>
                        <BR>
                </DIV></TD>
              </TR>
              <TR align="center" class="content02">
                <TD bgColor=#ffffff><a href="bgimg/cps800bg04.jpg" target="_blank"><img src="bgimg/smalcps800bg04.jpg" alt="&lt;img border='0'  width='400' height='223' src='bgimg/cps800bg04.jpg'&gt;" width="151" height="83" border="0"></a><br>
                  主题4</TD>
                <TD bgColor=#ffffff><a href="bgimg/cps800bg05.jpg" target="_blank"><img src="bgimg/smalcps800bg05.jpg" alt="&lt;img border='0'  width='400' height='223' src='bgimg/cps800bg05.jpg'&gt;" width="151" height="83" border="0"></a><br>
                  主题5</TD>
                <TD bgColor=#ffffff><a href="bgimg/cps800bg06.jpg" target="_blank"><img src="bgimg/smalcps800bg06.jpg" alt="&lt;img border='0'  width='400' height='223' src='bgimg/cps800bg06.jpg'&gt;" width="151" height="83" border="0"></a><br>
                  主题6</TD>
              </TR>
            </TBODY>
          </TABLE>
          <br></TD>
    </TR>
  </TBODY>
</TABLE>
</BODY></HTML>