var __isIE =  navigator.appVersion.match(/MSIE/);   
var __userAgent = navigator.userAgent;   
var __isFireFox = __userAgent.match(/firefox/i);   
var __isFireFoxOld = __isFireFox && (__userAgent.match(/firefox\/2./i) || __userAgent.match(/firefox\/1./i));   
var __isFireFoxNew = __isFireFox && !__isFireFoxOld;   
  
  
function __parseBorderWidth(width) {   
    var res = 0;   
    if (typeof(width) == "string" && width != null && width != "" ) {   
        var p = width.indexOf("px");   
        if (p >= 0) {   
            res = parseInt(width.substring(0, p));   
        }   
        else {   
            //do not know how to calculate other values (such as 0.5em or 0.1cm) correctly now   
            //so just set the width to 1 pixel   
            res = 1;    
        }   
    }   
    return res;   
}   
  
  
//returns border width for some element   
function __getBorderWidth(element) {   
    var res = new Object();   
    res.left = 0; res.top = 0; res.right = 0; res.bottom = 0;   
    if (window.getComputedStyle) {   
        //for Firefox   
        var elStyle = window.getComputedStyle(element, null);   
        res.left = parseInt(elStyle.borderLeftWidth.slice(0, -2));     
        res.top = parseInt(elStyle.borderTopWidth.slice(0, -2));     
        res.right = parseInt(elStyle.borderRightWidth.slice(0, -2));     
        res.bottom = parseInt(elStyle.borderBottomWidth.slice(0, -2));     
    }   
    else {   
        //for other browsers   
        res.left = __parseBorderWidth(element.style.borderLeftWidth);   
        res.top = __parseBorderWidth(element.style.borderTopWidth);   
        res.right = __parseBorderWidth(element.style.borderRightWidth);   
        res.bottom = __parseBorderWidth(element.style.borderBottomWidth);   
    }   
      
    return res;   
}   
  
//returns absolute position of some element within document   
function getAbsolutePos(element) {   
    var res = new Object();   
    res.x = 0; res.y = 0;   
    if (element !== null) {   
        res.x = element.offsetLeft;   
        res.y = element.offsetTop;   
           
        var offsetParent = element.offsetParent;   
        var parentNode = element.parentNode;   
        var borderWidth = null;   
  
        while (offsetParent != null) {   
            res.x += offsetParent.offsetLeft;   
            res.y += offsetParent.offsetTop;   
               
            var parentTagName = offsetParent.tagName.toLowerCase();    
  
            if ((__isIE && parentTagName != "table") || (__isFireFoxNew && parentTagName == "td")) {               
                borderWidth = __getBorderWidth(offsetParent);   
                res.x += borderWidth.left;   
                res.y += borderWidth.top;   
            }   
               
            if (offsetParent != document.body && offsetParent != document.documentElement) {   
                res.x -= offsetParent.scrollLeft;   
                res.y -= offsetParent.scrollTop;   
            }   
  
            //next lines are necessary to support FireFox problem with offsetParent   
            if (!__isIE) {   
                while (offsetParent != parentNode && parentNode !== null) {   
                    res.x -= parentNode.scrollLeft;   
                    res.y -= parentNode.scrollTop;   
                       
                    if (__isFireFoxOld) {   
                        borderWidth = kGetBorderWidth(parentNode);   
                        res.x += borderWidth.left;   
                        res.y += borderWidth.top;   
                    }   
                    parentNode = parentNode.parentNode;   
                }       
            }   
  
            parentNode = offsetParent.parentNode;   
            offsetParent = offsetParent.offsetParent;   
        }   
    }   
    return res;   
}