function openMenu() {
  document.getElementById("menu").style.display = "block";
}

function closeMenu() {
  document.getElementById("menu").style.display = "none";
}

function closeAboutPopup() {
  document.getElementById("popup-about").style.display = "none";
}

function openAboutPopup() {
  document.getElementById("popup-about").style.display = "block";
}

function closeTiplocPopup() {
  document.getElementById("popup-tiploc").style.display = "none";
}

function openTiplocPopup() {
  document.getElementById("popup-tiploc").style.display = "block";
}