nv.utils.windowSize = function() {
    // Sane defaults
    var size = {width: 640, height: 480};

    // Earlier IE uses Doc.body
    if (document.body && document.body.offsetWidth) {
        size.width = document.body.offsetWidth;
        size.height = document.body.offsetHeight;
    }

    // IE can use depending on mode it is in
    if (document.compatMode=='CSS1Compat' &&
        document.documentElement &&
        document.documentElement.offsetWidth ) {
        size.width = document.documentElement.offsetWidth;
        size.height = document.documentElement.offsetHeight;
    }

    // Most recent browsers use
    if (window.innerWidth && window.innerHeight) {
        size.width = window.innerWidth;
        size.height = window.innerHeight;
    }
    return (size);
};