function copyLink(link) {
   var el = document.createElement('textarea');
   el.value = link;
   el.setAttribute('readonly', '');
   el.style = {position: 'absolute', left: '-9999px'};
   document.body.appendChild(el);
   el.select();
   document.execCommand('copy');
   document.body.removeChild(el);
   alert("Link wurde kopiert");
}
function openWindow(window_name) {
  document.getElementById("window-" + window_name).style.display = "block";
  document.getElementById("window-" + window_name).style.opacity = "1";
  document.getElementById("back-arrow").style.display = "none";
  document.getElementById("back-arrow-window").style.display = "block";
  document.getElementById("main").style.filter = "blur(8px)";
}
function closeWindow(site_name) {
  if (site_name == "1") {
    document.getElementById("window-1").style.display = "none";
    document.getElementById("window-1").style.opacity = "0";
    document.getElementById("window-2").style.display = "none";
    document.getElementById("window-2").style.opacity = "0";
    document.getElementById("window-3").style.display = "none";
    document.getElementById("window-3").style.opacity = "0";
  }
  if (site_name == "2") {
    document.getElementById("window-4").style.display = "none";
    document.getElementById("window-4").style.opacity = "0";
  }
  if (site_name == "3") {
    document.getElementById("window-5").style.display = "none";
    document.getElementById("window-5").style.opacity = "0";
  }
  if (site_name == "4") {
    document.getElementById("window-6").style.display = "none";
    document.getElementById("window-6").style.opacity = "0";
  }
  document.getElementById("back-arrow").style.display = "block";
  document.getElementById("back-arrow-window").style.display = "none";
  document.getElementById("main").style.filter = "blur(0px)";
}
function addTo(from) {
  var from = from;
  var selectedValue = document.getElementById('add-to').value;
  window.location = 'add-vokab?from=' + from + '&add-to' + selectedValue;
}
function openSchoolYear() {
  var selectedValue = document.getElementById('openSchoolYear').value;
  window.location = '?item=' + selectedValue;
}
function togglePassword(fieldNumber) {
  var x = document.getElementById("toggle-password" + fieldNumber);
  if (x.type === "password") {
    x.type = "text";
    document.getElementById("toggle-password-chb" + fieldNumber + "-eye").style.visibility = "hidden";
    document.getElementById("toggle-password-chb" + fieldNumber + "-eye-slash").style.visibility = "visible";
  } else {
    x.type = "password";
    document.getElementById("toggle-password-chb" + fieldNumber + "-eye").style.visibility = "visible";
    document.getElementById("toggle-password-chb" + fieldNumber + "-eye-slash").style.visibility = "hidden";
  }
}