// check if the browser is Navigator 3 or higher:

agent = navigator.userAgent;

browserVer = 2;
if (agent.substring(0,7) == "Mozilla")
{if (parseInt(agent.substring(8,9)) >= 3) {browserVer = 1;}}


if (browserVer == 1) 
{

home1 = new Image(20,60);
home1.src = "images/b_top1.gif";
home2 = new Image(20,60);
home2.src = "images/b_top1a.gif";
map1 = new Image(20,60);
map1.src = "images/b_top2.gif";
map2 = new Image(20,60);
map2.src = "images/b_top2a.gif";
mail1 = new Image(20,60);
mail1.src = "images/b_top3.gif";
mail2 = new Image(20,60);
mail2.src = "images/b_top3a.gif";


}
function hiLite(imgSrc, imgTextID) 
{
  if (browserVer == 1) {document.images[imgTextID].src = eval(imgSrc + ".src")}
}

function redirect(obj)
{ 
  var id = obj.item(obj.selectedIndex).value;
  document.location="apparatus"+id+".html";
}

// add to favorites

function favorites(url,title)
{
  if ((navigator.appName == "Microsoft Internet Explorer") && (parseInt(navigator.appVersion) >= 4))
 {
  window.external.AddFavorite(url,title);
 } 
  else if (navigator.appName == "Netscape")
 {
    window.sidebar.addPanel(title,url,"");
 } else 
 {
    alert("Press CTRL-D (Netscape) or CTRL-T (Opera) to bookmark");
 }
}