text: window.onload = startUp;
  
  var index = 0;
  var interval;
  var images = [
      "1.jpg",
      "2.jpg",
      "3.jpg",
      "4.jpg"
  ];
  
  function startUp() {
      timer();
      var interval = setInterval(timer, 2000);
  }
  
  function timer() {
      var wrapper = document.getElementById("wrapper");
      wrapper.innerHTML = '<img src="images/' + images[index] + '" alt="Et bilde">';
      index++;
      if (index == images.length) {
          index = 0;
      }
  }
  