function changer(from,to) {
	if(document.images) {
		document.images[from].src = to;
	}
}

$(document).ready(function() {
	
	$("ul#topnav li").hover(function() { //Hover over event on list item
		$(this).css({ 'background' : 'none'}); //Add background color + image on hovered list item
		$(this).find("span").show(); //Show the subnav
	} , function() { //on hover out...
		$(this).css({ 'background' : 'none'}); //Ditch the background
		$(this).find("span").hide(); //Hide the subnav
	});
		
});