here are some valuable javascript functions for getting window width and height a long with the get element X position, and Y position all of this functions are not my invention; its copied from the website and blog listed in the reference list.

 lets start with getWindowDimension:

function getWindowDime­nsion(isWidth) 
   var winW = 630, winH = 460;
   if (parseInt(navigator.appVersion)>3) {
­       if (navigator.appName=="Netscape") {
           winW = window.innerWidth-16;
           winH = window.innerHeight-16;
       }
       if (navigator.appName.indexOf("Microsoft")!=-1) {
           winW = document.body.offsetWidth-20;
           winH = document.body.offsetHeight-20;­
       }
   }
   return (isWidth)? winW : winH;
}

the following are getXPosition and getYPosition:

function findPosX(obj) {    
    var curleft = 0;
    if(obj.offsetParent) {
        while(1) {
            curleft += obj.offsetLeft;
            if(!obj.offsetParent)
                break;
            obj = obj.offsetParent;
        } 
    } else if(obj.x)
        curleft += obj.x;
    return curleft;
}
    
function findPosY(obj) {
    var curtop = 0;
    if(obj.offsetParent) {
        while(1) {
            curtop += obj.offsetTop;
            if(!obj.offsetParent)
                break;
            obj = obj.offsetParent;
        }
    } else if(obj.y)
        curtop += obj.y;
    return curtop;
}

­

References:­

• http://www.javascripter.net/faq/browserw.htm
• http://blog.firetree.net/2005/07/04/javascript-find-position/