// JavaScript Documentfunction shownav(which) {	var nav_basename = "thumbnails_";	var nav_count = 0;	while ($(nav_basename+(nav_count+1)) != null) {    nav_count++;	}	//close other nav items	for (i=1;i<=nav_count;i++) {    $(nav_basename+i).style.display = "none";	}	$('thumbnails_'+which).style.display = "block";}function hidenav() {	var nav_basename = "thumbnails_";	var nav_count = 0;	while ($(nav_basename+(nav_count+1)) != null) {    nav_count++;	}	//close other nav items	for (i=1;i<=nav_count;i++) {    $(nav_basename+i).style.display = "none";	}}