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';
}