function getWindowHeight() {
    var windowHeight=0;
    if (typeof(window.innerHeight)=='number') {
        windowHeight=window.innerHeight;
    }
    else {
     if (document.documentElement&&
       document.documentElement.clientHeight) {
         windowHeight = document.documentElement.clientHeight;
    }
    else {
     if (document.body&&document.body.clientHeight) {
         windowHeight=document.body.clientHeight;
      }
     }
    }
    return windowHeight;
}

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


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