var bName = navigator.appName;
var bVer = parseInt(navigator.appVersion);
var ver = 0;
var path = self.location.pathname;
var code = path.substring(0,4);

if (bName == "Netscape" && bVer >= 3)
 {ver = 2;}
if (bName == "Microsoft Internet Explorer" && bVer >= 4)
 {ver = 1;}

function img_on(imgName)
 {if (ver >= 1)
  {document[imgName].src = eval(imgName + "on.src");
  }
 }

function img_off(imgName)
 {if (ver >= 1)
  {document[imgName].src = eval(imgName + "off.src");
  }
 }