function getWindowHeight() {
    var windowHeight = 0;
        if (window.innerHeight || document.documentElement.clientHeight || document.body.clientHeight) {
        windowHeight = window.innerHeight || document.documentElement.clientHeight || document.body.clientHeight;
        }
    return windowHeight;
    }

function setFooter() {
    if (document.getElementById) {
        var windowHeight = getWindowHeight();
        if (windowHeight > 0) {
            var contentHeight = document.getElementById('centerSectionWrapper').offsetHeight;
            var footerElement = document.getElementById('webappFooter');
            var footerHeight  = footerElement.offsetHeight;
            if (windowHeight - (contentHeight + footerHeight) >= 0) {
                footerElement.style.top = (windowHeight - (contentHeight + footerHeight)) + 'px';
            }
            else {
                footerElement.style.top = '0px';
            }
        }
    }
}

window.onload = function() {
    setFooter();
}
window.onresize = function() {
    setFooter();
}