onmouseover hide/show description block: cross Browser problem

[aotash]

This javascript shows and hides description (like alt in image tag). It works in IE but not in Mozilla, what is wrong please help:

<SCRIPT LANGUAGE="JavaScript">
 
// ############## SIMPLE BROWSER SNIFFER
if (document.layers) {navigator.family = "nn4"}
if (document.all) {navigator.family = "ie4"}
if (window.navigator.userAgent.toLowerCase().match("gecko")) {navigator.family = "gecko"}
 
// ######### popup text
descarray = new Array(
"This site has some of the greatest scripts around!"
);
 
overdiv="0";
// ######### CREATES POP UP BOXES
function popLayer(a){
if(!descarray[a]){descarray[a]="<font color=red>This popup (#"+a+") isn't setup correctly - needs description</font>";}
if (navigator.family == "gecko") {pad="0"; bord="1 bordercolor=black";}
else {pad="1"; bord="0";}
desc = "<table cellspacing=0 cellpadding="+pad+" border="+bord+" bgcolor=000000><tr><td>\n"
+"<table cellspacing=0 cellpadding=3 border=0 width=100%><tr><td bgcolor=ffffdd><center><font size=-1>\n"
+descarray[a]
+"\n</td></tr></table>\n"
+"</td></tr></table>";
if(navigator.family =="nn4") {
document.object1.document.write(desc);
document.object1.document.close();
document.object1.left=x+15;
document.object1.top=y-5;
}
else if(navigator.family =="ie4"){
object1.innerHTML=desc;
object1.style.pixelLeft=x+15;
object1.style.pixelTop=y-5;
}
else if(navigator.family =="gecko"){
document.getElementById("object1").innerHTML=desc;
document.getElementById("object1").style.left=x+15;
document.getElementById("object1").style.top=y-5;
}
}
function hideLayer(){
if (overdiv == "0") {
if(navigator.family =="nn4") {eval(document.object1.top="-500");}
else if(navigator.family =="ie4"){object1.innerHTML="";}
else if(navigator.family =="gecko") {document.getElementById("object1").style.top="-500";}
}
}
 
// ######## TRACKS MOUSE POSITION FOR POPUP PLACEMENT
var isNav = (navigator.appName.indexOf("Netscape") !=-1);
function handlerMM(e){
x = (isNav) ? e.pageX : event.clientX + document.body.scrollLeft;
y = (isNav) ? e.pageY : event.clientY + document.body.scrollTop;
}
if (isNav){document.captureEvents(Event.MOUSEMOVE);}
document.onmousemove = handlerMM;
// End -->
</script>

==========================================
and body:

[HTML]<div id="object1" style="position:absolute; background-color:FFFFDD;color:black;border-color:black;border-width:20; visibility:show; left:25px; top:-100px; z-index:+1" onmouseover="overdiv=1;" onmouseout="overdiv=0; setTimeout('hideLayer()',1000)">
pop up description layer
</div>

<a href="#" onMouseOver="popLayer(0)" onMouseOut="hideLayer()"><font size=-1 face=arial><b>THE JavaScript Source</b></font></a>

[/HTML]thanks.

[acoder]

Welcome to TSDN!

The code uses browser detection - it would be better using object/feature detection, but anyway...

Firefox/Mozilla requires you to give units, e.g. "px" for the position properties (top, left, etc.)