function getPageSize() {
    var xScroll, yScroll;

    if (window.innerHeight && window.scrollMaxY) {
        xScroll = window.innerWidth + window.scrollMaxX;
        yScroll = window.innerHeight + window.scrollMaxY;
    } else if (document.body.scrollHeight > document.body.offsetHeight) { // all but Explorer Mac
        xScroll = document.body.scrollWidth;
        yScroll = document.body.scrollHeight;
    } else { // Explorer Mac...would also work in Explorer 6 Strict, Mozilla and Safari
        xScroll = document.body.offsetWidth;
        yScroll = document.body.offsetHeight;
    }

    var windowWidth, windowHeight;

    if (self.innerHeight) {	// all except Explorer
        if (document.documentElement.clientWidth) {
            windowWidth = document.documentElement.clientWidth;
        } else {
            windowWidth = self.innerWidth;
        }
        windowHeight = self.innerHeight;
    } else if (document.documentElement && document.documentElement.clientHeight) { // Explorer 6 Strict Mode
        windowWidth = document.documentElement.clientWidth;
        windowHeight = document.documentElement.clientHeight;
    } else if (document.body) { // other Explorers
        windowWidth = document.body.clientWidth;
        windowHeight = document.body.clientHeight;
    }

    // for small pages with total height less then height of the viewport
    if (yScroll < windowHeight) {
        pageHeight = windowHeight;
    } else {
        pageHeight = yScroll;
    }

    // for small pages with total width less then width of the viewport
    if (xScroll < windowWidth) {
        pageWidth = xScroll;
    } else {
        pageWidth = windowWidth;
    }

    return [pageWidth, pageHeight];
}