var d=document;
function setFooter() {
 d.getElementById('footer').style.visibility = 'hidden';
 d.getElementById('footer').style.bottom = '';

 if(d.all) {
  d.getElementById('footer').style.bottom = '0px';
  if(d.getElementById('footer').offsetTop < d.body.offsetHeight) {
   d.getElementById('footer').style.bottom = '';
  }
 }
 else {
  if(window.innerHeight > (d.body.offsetHeight+20)) {
   d.getElementById('footer').style.bottom = '0px';
  }
 }
 d.getElementById('footer').style.visibility = 'visible';
}
window.onresize = function() {
 setFooter();
}