sfHover = function() { 
  var sfEls = document.getElementById("nav").getElementsByTagName("LI"); 
  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); 

function setButton(id, path)
{
  document.getElementById(id).src = path;
}