Querying the scrollbar positions of a window

gistfile1.js

// Return the current scrollbar offsets as the x and y properties of an object
function getScrollOffsets(w) {
    // Use the specified window or the current window if no argument
    w = w || window;
    // This works for all browsers except IE versions 8 and before
    if (w.pageXOffset != null) return {x: w.pageXOffset, y:w.pageYOffset};
    // For IE (or any browser) in Standards mode
    var d = w.document;
    if (document.compatMode == "CSS1Compat") return {x:d.documentElement.scrollLeft, y:d.documentElement.scrollTop};
    // For browsers in Quirks mode
    return { x: d.body.scrollLeft, y: d.body.scrollTop };
}