function rollOver(imageName, menuImageFile){
		if(parseInt(navigator.appVersion)>=4){
				document.images[imageName].src = menuImageFile;
		}
}

function menu_actief(li_name,img){
	document.getElementById(li_name).style.backgroundImage='url('+img+')';
}
function menu_deactief(li_name){
 document.getElementById(li_name).style.backgroundImage='none';
}