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 Pic (picture) {
  document.getElementById("main").src = picture;
}