function changecontent(box,nr) {
  temp = box;
  switch (nr) {
    case 1:
    document.getElementById("contentdiv").innerHTML = box1;
    break;
    case 2:
    document.getElementById("contentdiv").innerHTML = box2;
    break;
    case 3:
    document.getElementById("contentdiv").innerHTML = box3;
    break;
    case 4:
    document.getElementById("contentdiv").innerHTML = box4;
    break;
    case 5:
    document.getElementById("contentdiv").innerHTML = box5;
    break;
    case 6:
    document.getElementById("contentdiv").innerHTML = box6;
    break;
  }
}

function repaircontent() {
  document.getElementById("contentdiv").innerHTML = temp;
}