ok = false; pick = 0;
if (navigator.userAgent.indexOf ("Mozilla") != -1) {
  ok = parseInt(navigator.appVersion.substring(0,1)) >= 3
} else {}

   if (ok == 1) {
      number0 = new Image(300,15)
      number0.src = "images/txet.gif"
      number1 = new Image(300,15)
      number1.src = "images/txet1.gif"
      number2 = new Image(300,15)
      number2.src = "images/txet2.gif"
      number3 = new Image(300,15)
      number3.src = "images/txet3.gif"
      number4 = new Image(300,15)
      number4.src = "images/txet4.gif"
   }

   function un(nom) {
       if (ok == 1) {
          if (nom == "n1") {document.number.src = number1.src; }
          if (nom == "n2") {document.number.src = number2.src; }
          if (nom == "n3") {document.number.src = number3.src; }
          if (nom == "n4") {document.number.src = number4.src; }
          return true;
       }
   }

   function deux() {
       if (ok == 1) {
          document.number.src = number0.src;
          return true;
       }
   }