function image_swap(myID)
{
   var strOver  = "_on"
   var strOff = "_off"
   var oSpan = document.getElementById(myID)
   var currentAlphaImg = oSpan.src
   
   if (currentAlphaImg.indexOf(strOver) != -1)
      oSpan.src = currentAlphaImg.replace(strOver,strOff)
   else
      oSpan.src = currentAlphaImg.replace(strOff,strOver)
}


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);