function toggleLayer( id )
{   
    var elem, vis;
    if( document.getElementById ) // this is the way the standards work
        elem = document.getElementById( id );
    else if( document.all ) // this is the way old msie versions work
        elem = document.all[id];
    else if( document.layers ) // this is the way nn4 works
        elem = document.layers[id];
    vis = elem.style;
    // if the style.display value is blank we try to figure it out here
    if(vis.display==''&&elem.offsetWidth!=undefined&&elem.offsetHeight!=undefined)
        vis.display = (elem.offsetWidth!=0&&elem.offsetHeight!=0)?'block':'none';
    vis.display = (vis.display==''||vis.display=='block')?'none':'block';

}

var __isFireFox = navigator.userAgent.match(/gecko/i);

  
//returns the absolute position of some element within document
function GetElementAbsolutePos(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;

        while (offsetParent !== null) {
            res.x += offsetParent.offsetLeft;
            res.y += offsetParent.offsetTop;

            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 (__isFireFox) {
                while (offsetParent != parentNode && parentNode !== null) {
                    res.x -= parentNode.scrollLeft;
                    res.y -= parentNode.scrollTop;

                    parentNode = parentNode.parentNode;
                }
            }
            parentNode = offsetParent.parentNode;
            offsetParent = offsetParent.offsetParent;
        }
    }
    return res;
}