browser_name = navigator.appName;
 browser_version = parseFloat(navigator.appVersion);
 if (browser_name == "Netscape" && browser_version >= 3.0) { roll = 'true'; }
 else if (browser_name == "Microsoft Internet Explorer" && browser_version >= 3.0) {
     roll = 'true'; }
 else { roll = 'false'; }
 function over(img,ref) { if (roll == 'true') { document.images[img].src = ref; } }
 function out(img,ref) { if (roll == 'true') { document.images[img].src = ref; } }
 if (roll == 'true') {
  Top     = new Image; Top.src    = "i/ar-bot.gif";
  Bot     = new Image; Bot.src    = "i/ar-tobot-over.gif";
  Left     = new Image; Left.src    = "i/to-left-over.gif";
  Right     = new Image; Right.src    = "i/to-right-over.gif";
 }