以下都不行：

function getOffset(e) {
    var t = e.offsetTop;
    var l = e.offsetLeft;
    while (e = e.offsetParent) {
        t += e.offsetTop;
        l += e.offsetLeft;
    }
    var rec = new Array(1);
    rec[0] = t;
    rec[1] = l;
    return rec;
}

function getPoint(source) {
    var pt = { x: 0, y: 0 };
//    do {
//        pt.x += source.offsetLeft;
//        pt.y += source.offsetTop;
//        source = source.offsetParent;
//    }
    //    while (source);
    pt.x = source.getBoundingClientRect().left + getHScroolPos();
    pt.y = source.getBoundingClientRect().top + getVScroolPos();
    return pt;
}