function xstooltip_findPosX(obj) 
        {
          var curleft = 0;
          if (obj.offsetParent) 
          {
            while (obj.offsetParent) 
                {
                    curleft += obj.offsetLeft
                    obj = obj.offsetParent;
                }
            }
            else if (obj.x)
                curleft += obj.x;
            return curleft;
        }

        function xstooltip_findPosY(obj) 
        {
            var curtop = 0;
            if (obj.offsetParent) 
            {
                while (obj.offsetParent) 
                {
                    curtop += obj.offsetTop
                    obj = obj.offsetParent;
                }
            }
            else if (obj.y)
                curtop += obj.y;
            return curtop;
        }

        function xstooltip_show(tooltipId, parentId, posX, posY)
        {
            it = document.getElementById(tooltipId);
            
            if ((it.style.top == '' || it.style.top == 0) 
                && (it.style.left == '' || it.style.left == 0))
            {
                // need to fixate default size (MSIE problem)
                it.style.width = it.offsetWidth + 'px';
                it.style.height = it.offsetHeight + 'px';
                
                img = document.getElementById(parentId); 
            
                // if tooltip is too wide, shift left to be within parent 
                if (posX + it.offsetWidth > img.offsetWidth) posX = img.offsetWidth - it.offsetWidth;
                if (posX < 0 ) posX = 0; 
                
                x = xstooltip_findPosX(img) + posX;
                y = xstooltip_findPosY(img) + posY;
                
                it.style.top = y + 'px';
                it.style.left = x + 'px';
            }
            
            it.style.visibility = 'visible'; 
        }

        function xstooltip_hide(id)
        {
            it = document.getElementById(id); 
            it.style.visibility = 'hidden'; 
        }