function SwitchMenu(obj) {
  if (document.getElementById) {
    var el = document.getElementById(obj);
    var ar = document.getElementById("map_class").getElementsByTagName("div");
    
    if (el.style.display != "block") {
      for (var i = 0; i < ar.length; i++) {
        ar[i].style.display = "none";
      }
      el.style.display = "block";
    }
  }
}