JavaScript tool tip pop up in IE8

i have been trying to get a JavaScript tool tip pop up working correctly, the pop up works fine except the position doesnt work properly in IE8

in firefox the position is correct and remains correct even if the window is scrolled.

however in IE8 the position is correct if the window isnt scrolled but if the window is scrolled then the tooltip moves away from it anchor point up the screen equal distance of the amount the window is scrolled down.

you can see this in action here by mousing over the link "Go Direct To Dating Direct"
http://www.online-dating-reviews.co.uk/index.asp?page=retailer_details&option=shopping&p3=12861

the main code is below

the link triger code is:
<a href="thispage.html" onmouseover="doTooltip(event,0)" onmouseout="hideTip()">text</a>

postional display div is as follows, and is placed just before the end body tag:
<div id="tipDiv" style="position:absolute; visibility:hidden; z-index:100"></div>

can anybody please help with the possitional correction for IE8

thank you

<script language="javascript" type="text/javascript">

// This code is from Dynamic Web Coding www.dyn-web.com
// Copyright 2002 by Sharon Paine Permission granted to use this code as long as this entire notice is included.
// Courtesy of SimplytheBest.net - http://simplythebest.net/scripts/

var dom = (document.getElementById) ? true : false;
var ns5 = ((navigator.userAgent.indexOf("Gecko")>-1) && dom) ? true: false;
var ie5 = ((navigator.userAgent.indexOf("MSIE")>-1) && dom) ? true : false;
var ns4 = (document.layers && !dom) ? true : false;
var ie4 = (document.all && !dom) ? true : false;
var nodyn = (!ns5 && !ns4 && !ie4 && !ie5) ? true : false;

var origWidth, origHeight;
if (ns4) {
	origWidth = window.innerWidth; origHeight = window.innerHeight;
	window.onresize = function() { if (window.innerWidth != origWidth || window.innerHeight != origHeight) history.go(0); }
}

if (nodyn) { event = "nope" }
var tipFollowMouse	= true;
var tipWidth		= 160;
var offX		 	= 12;	// how far from mouse to show tip
var offY		 	= -130;
var tipFontFamily 	= "Verdana, arial, helvetica, sans-serif";
var tipFontSize		= "8pt";
var tipFontColor		= "#000000";
var tipBgColor		= "#DDECFF";
var origBgColor 		= tipBgColor; // in case no bgColor set in array
var tipBorderColor 	= "#000080";
var tipBorderWidth 	= 2;
var tipBorderStyle 	= "ridge";
var tipPadding	 	= 4;




var messages = new Array();
messages[0] = new Array('http://www.tqlkg.com/image-2636075-10485262','Last order date for<br />Christmas delivery.<br />20th December',"#FFFFFF");


if (document.images) {
	var theImgs = new Array();
	for (var i=0; i<messages.length; i++) {
  	theImgs[i] = new Image();
		theImgs[i].src = messages[i][0];
  }
}

var startStr = '<table width="' + tipWidth + '"><tr><td align="center" width="100%"><img src="';
var midStr = '" border="0"></td></tr><tr><td valign="top">';
var endStr = '</td></tr></table>';

var tooltip, tipcss;
function initTip() {
	if (nodyn) return;
	tooltip = (ns4)? document.tipDiv.document: (ie4)? document.all['tipDiv']: (ie5||ns5)? document.getElementById('tipDiv'): null;
	tipcss = (ns4)? document.tipDiv: tooltip.style;
	if (ie4||ie5||ns5) {	// ns4 would lose all this on rewrites
		tipcss.width = tipWidth+"px";
		tipcss.fontFamily = tipFontFamily;
		tipcss.fontSize = tipFontSize;
		tipcss.color = tipFontColor;
		tipcss.backgroundColor = tipBgColor;
		tipcss.borderColor = tipBorderColor;
		tipcss.borderWidth = tipBorderWidth+"px";
		tipcss.padding = tipPadding+"px";
		tipcss.borderStyle = tipBorderStyle;
	}
	if (tooltip&&tipFollowMouse) {
		if (ns4) document.captureEvents(Event.MOUSEMOVE);
		document.onmousemove = trackMouse;
	}
}

window.onload = initTip;

var t1,t2;	// for setTimeouts
var tipOn = false;	// check if over tooltip link
function doTooltip(evt,num) {

	if (!tooltip) return;
	if (t1) clearTimeout(t1);	if (t2) clearTimeout(t2);
	tipOn = true;
	// set colors if included in messages array
	if (messages[num][2])	var curBgColor = messages[num][2];
	else curBgColor = tipBgColor;
	if (messages[num][3])	var curFontColor = messages[num][3];
	else curFontColor = tipFontColor;
	if (ns4) {
		var tip = '<table bgcolor="' + tipBorderColor + '" width="' + tipWidth + '" cellspacing="0" cellpadding="' + tipBorderWidth + '" border="0"><tr><td><table bgcolor="' + curBgColor + '" width="100%" cellspacing="0" cellpadding="' + tipPadding + '" border="0"><tr><td>'+ startStr + messages[num][0] + midStr + '<span style="font-family:' + tipFontFamily + '; font-size:' + tipFontSize + '; color:' + curFontColor + ';">' + messages[num][1] + '</span>' + endStr + '</td></tr></table></td></tr></table>';
		tooltip.write(tip);
		tooltip.close();
	} else if (ie4||ie5||ns5) {
		var tip = startStr + messages[num][0] + midStr + '<span style="font-family:' + tipFontFamily + '; font-size:' + tipFontSize + '; color:' + curFontColor + ';">' + messages[num][1] + '</span>' + endStr;
		tipcss.backgroundColor = curBgColor;
	 	tooltip.innerHTML = tip;
	}
	if (!tipFollowMouse) positionTip(evt);
	else t1=setTimeout("tipcss.visibility='visible'",100);
}

var mouseX, mouseY;
function trackMouse(evt) {
	mouseX = (ns4||ns5)? evt.pageX: window.event.clientX + document.body.scrollLeft;
	mouseY = (ns4||ns5)? evt.pageY: window.event.clientY + document.body.scrollTop;
	if (tipOn) positionTip(evt);
}

function positionTip(evt) {
	if (!tipFollowMouse) {
		mouseX = (ns4||ns5)? evt.pageX: window.event.clientX + document.body.scrollLeft;
		mouseY = (ns4||ns5||ie8)? evt.pageY: window.event.clientY + document.body.scrollTop;
	}
	// tooltip width and height
	var tpWd = (ns4)? tooltip.width: (ie4||ie5)? tooltip.clientWidth: tooltip.offsetWidth;
	var tpHt = (ns4)? tooltip.height: (ie4||ie5)? tooltip.clientHeight: tooltip.offsetHeight;
	// document area in view (subtract scrollbar width for ns)
	var winWd = (ns4||ns5)? window.innerWidth-20+window.pageXOffset: document.body.clientWidth+document.body.scrollLeft;
	var winHt = (ns4||ns5)? window.innerHeight-20+window.pageYOffset: document.body.clientHeight+document.body.scrollTop;
	// check mouse position against tip and window dimensions
	// and position the tooltip
	if ((mouseX+offX+tpWd)>winWd)
		tipcss.left = (ns4)? mouseX-(tpWd+offX): mouseX-(tpWd+offX)+"px";
	else tipcss.left = (ns4)? mouseX+offX: mouseX+offX+"px";
	if ((mouseY+offY+tpHt)>winHt)
		tipcss.top = (ns4)? winHt-(tpHt+offY): winHt-(tpHt+offY)+"px";
	else tipcss.top = (ns4)? mouseY+offY: mouseY+offY+"px";
	if (!tipFollowMouse) t1=setTimeout("tipcss.visibility='visible'",100);
}

function hideTip() {
	if (!tooltip) return;
	t2=setTimeout("tipcss.visibility='hidden'",100);
	tipOn = false;
}

</script>

Select allOpen in new window