Hvordan beregner jeg en fast afstand i dette script

Hej!

Jeg bruger følgende javascript ... til at genere mouse-over-tips med.
Det fungerer fint, bortset fra at jeg godt kunne tænke mig at "låse" tooltipsene, så de stod på samme afstand fra venstre side af skærmbilledet - i forhold til skærmopløsning.

Jeg er godt klar over at jeg skal sætte "tipcss.left" - men hvordan laver jeg en ny beregning, så tooltippet altid har samme X-værdi - men altså uden at være et fast antal pixels, men i forhold til skærmopløsningen?

Kan man dét?

/*
Image w/ description tooltip- By Dynamic Web Coding (www.dyn-web.com)
Copyright 2002 by Sharon Paine
Visit http://www.dynamicdrive.com for this script
*/
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;

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

// avoid error of passing event object in older browsers
if (nodyn) { event = "nope" }

///////////////////////  CUSTOMIZE HERE  ////////////////////
// settings for tooltip
// Do you want tip to move when mouse moves over link?
var tipFollowMouse= true;   
// Be sure to set tipWidth wide enough for widest image
//var tipWidth= 200;
var offX= 20;    // how far from mouse to show tip
var offY= 12;
//var tipFontFamily= "Verdana, arial, helvetica, sans-serif";
//var tipFontSize= "8pt";
// set default text color and background color for tooltip here
// individual tooltips can have their own (set in messages arrays)
// but don't have to
//var tipFontColor= "#000000";
//var tipBgColor= "#DDECFF";
var tipBorderColor= "#000000";
var tipBorderWidth= 1;
var tipBorderStyle= "solid";
var tipPadding= 0;
var tipSpacing= 0;

// tooltip content goes here (image, description, optional bgColor, optional textcolor)
var messages = new Array();
// multi-dimensional arrays containing:
// image and text for tooltip
// optional: bgColor and color to be sent to tooltip

////////////////////  END OF CUSTOMIZATION AREA  ///////////////////

// to layout image and text, 2-row table, image centered in top cell
// these go in var tip in doTooltip function
// startStr goes before image, midStr goes between image and text

//Fast defineret bredde
//var startStr2 = '<table cellspacing="0%" cellpadding="0%" width="' + tipWidth + '"><tr><td class="clsContentCellB2 clsTxtNormalC">';
//var startStr = '<table cellspacing="0%" cellpadding="0%" width="' + tipWidth + '"><tr><td class="clsContentCellB clsTxtNormalC">';

//Variabel bredde
var startStr2 = '<table cellspacing="0%" cellpadding="0%"><tr><td class="clsContentCellB2 clsTxtNormalC">';
var startStr = '<table cellspacing="0%" cellpadding="0%"><tr><td class="clsContentCellB clsTxtNormalC">';
var endStr = '</td></tr></table>';

////////////////////////////////////////////////////////////
//  initTip    - initialization for tooltip.
//        Global variables for tooltip.
//        Set styles for all but ns4.
//        Set up mousemove capture if tipFollowMouse set true.
////////////////////////////////////////////////////////////
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.spacing = tipSpacing+"px";   
        tipcss.borderStyle = tipBorderStyle;
    }
    if (tooltip&&tipFollowMouse) {
        if (ns4) document.captureEvents(Event.MOUSEMOVE);
        document.onmousemove = trackMouse;
    }
}

/////////////////////////////////////////////////
//  doTooltip function
//            Assembles content for tooltip and writes
//            it to tipDiv
/////////////////////////////////////////////////
var t1,t2;    // for setTimeouts
var tipOn = false;    // check if over tooltip link
function doTooltip(evt, tekst, num) {
  if(!tooltip){
    initTip();
  }
  if (!tooltip) return;
    if (t1) clearTimeout(t1);    if (t2) clearTimeout(t2);
    tipOn = true;
    // set colors if included in messages array
    if (ns4) {
      //no width
        var tip = '<table bgcolor="' + tipBorderColor + '" cellspacing="0" cellpadding="0" border="0"><tr><td><table width="100%" cellspacing="0" cellpadding="'+ tipBorderWidth +'" border="0"><tr><td>'+ startStr + tekst + endStr + '</td></tr></table></td></tr></table>';
        //with width
    //var tip = '<table bgcolor="' + tipBorderColor + '" width="' + tipWidth + '" cellspacing="0" cellpadding="0" border="0"><tr><td><table width="100%" cellspacing="0" cellpadding="'+ tipBorderWidth +'" border="0"><tr><td>'+ startStr + tekst + endStr + '</td></tr></table></td></tr></table>';
        tooltip.write(tip);
        tooltip.close();
    } else if (ie4||ie5||ns5){
        var tip;
        if(num%2==0){
        tip = startStr + tekst + endStr;
        }    else{
          tip = startStr2 + tekst + endStr;
        }
        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);
}

/////////////////////////////////////////////////////////////
//  positionTip function
//        If tipFollowMouse set false, so trackMouse function
//        not being used, get position of mouseover event.
//        Calculations use mouseover event position,
//        offset amounts and tooltip width to position
//        tooltip within window.
/////////////////////////////////////////////////////////////
function positionTip(evt) {
    if (!tipFollowMouse) {
        mouseX = (ns4||ns5)? evt.pageX: window.event.clientX + document.body.scrollLeft;
        mouseY = (ns4||ns5)? 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;
}