browserName = navigator.appName;         
   browserVer = parseInt(navigator.appVersion);  
   if (browserName == "Netscape" && browserVer >= 3) { 
      version = "n3";
   }
   else if (browserName == "Microsoft Internet Explorer" && browserVer >= 3) { 
      version = "n3";
   }
   else { 
   version="desconocido";
  }
        
 if (version == "n3") {
      toc1on = new Image();
        toc1on.src = "./i/x01.jpg";
      toc3on = new Image();
        toc3on.src = "./i/x03.jpg";
      toc4on = new Image();
        toc4on.src = "./i/x04.jpg";
        toc5on = new Image();
        toc5on.src = "./i/x05.jpg";
        toc6on = new Image();
        toc6on.src = "./i/x06.jpg";
        toc2on = new Image();
        toc2on.src = "./i/x02.jpg";


      toc6off = new Image();
        toc6off.src = "./i/m06.jpg";
      toc1off = new Image();
        toc1off.src = "./i/m01.jpg";
      toc3off = new Image();
        toc3off.src = "./i/m03.jpg";
      toc4off = new Image();
        toc4off.src = "./i/m04.jpg";
      toc5off = new Image();
        toc5off.src = "./i/m05.jpg";
      toc2off = new Image();
        toc2off.src = "./i/m02.jpg";
     
      }

function img_act(imgName) {
        if (version == "n3") {
        imgOn = eval(imgName + "on.src");
        document [imgName].src = imgOn;
        }
}

function img_inact(imgName) {
        if (version == "n3") {
        imgOff = eval(imgName + "off.src");
        document [imgName].src = imgOff;
        }
}