function changeTab(_numOfTab,_obj,_tabTotal) {
  var currentTab = document.getElementById("page" + _numOfTab);
  for (var x=1; x <=_tabTotal; x++) {
    document.getElementById("page" + x).style.visibility = "hidden";
    document.getElementById("page" + x).style.display = "none";
  }
    currentTab.style.visibility = "visible";
    currentTab.style.display = "inline";
    currentTab.className = "page";
  for (var x=1; x <=_tabTotal; x++) {
    document.getElementById("tab" + x).className = "";
  }
    document.getElementById("tab" + _numOfTab).className = "submenuselected";
}