agent = navigator.userAgent;
  browserVer = 2;
  //document.writeln (navigator.userAgent);
  if (agent.indexOf("a/3",6) == 6) {browserVer = 1};
  if (agent.indexOf("a/4",6) == 6) {browserVer = 1};

  // Cargar imágenes
  if (browserVer == 1) {
    
    b1 = new Image(72,19);
    b1.src = "imagenes/me1.gif";
    b1a = new Image(72,19);
    b1a.src = "imagenes/me1a.gif";

    b2 = new Image(79,19);
    b2.src = "imagenes/me2.gif";
    b2a = new Image(79,19);
    b2a.src = "imagenes/me2a.gif";
    
    b3 = new Image(101,19);
    b3.src = "imagenes/me3.gif";
    b3a = new Image(101,19);
    b3a.src = "imagenes/me3a.gif";


    b4 = new Image(104,19);
    b4.src = "imagenes/me4.gif";
    b4a = new Image(104,19);
    b4a.src = "imagenes/me4a.gif";


    b5 = new Image(85,19);
    b5.src = "imagenes/me5.gif";
    b5a = new Image(85,19);
    b5a.src = "imagenes/me5a.gif";

    b6 = new Image(84,19);
    b6.src = "imagenes/me6.gif";
    b6a = new Image(84,19);
    b6a.src = "imagenes/me6a.gif";

        
  }

  function marcar(imgDocID,imgObjName) {
    if (browserVer == 1) {
    document.images[imgDocID].src = eval(imgObjName + ".src")
    } 
  }