var sfHover = function() {
    var sfEls = document.getElementById('nav').getElementsByTagName('div');
    for (var i=0; i<sfEls.length; i++) {
      sfEls[i].onmouseover=function() {
	this.className+=' sfhover';
      }
      sfEls[i].onmouseout=function() {
	this.className=this.className.replace(new RegExp(' sfhover\\b'),'');
      }
    }
  }
if (window.attachEvent) window.attachEvent('onload',sfHover);