function DisplayElement(elementID) {
  // window.alert(elementID);
  var display = true;
  var ret = false;
  var element = document.getElementById(elementID);
  try {
    display = element.style.display != "none";
  }
  catch (exc) { };

  if (display) {
    element.style.display = "none";
    ret = false;
  }
  else {
    element.style.display = "block";
    ret = true;
  }
  return ret;
}

///---------------------------------------------------------------------

function DisplayElement(elementID, display) {
  var ret = false;
  var element = document.getElementById(elementID);
  try {
    display = element.style.display != "none";
  }
  catch (exc) { };

  if (display) {
    element.style.display = "none";
    ret = false;
  }
  else {
    element.style.display = "block";
    ret = true;
  }
  return ret;
}

//----------------------------------------------------------------------------


function anchor_click(link, LogItemsDivID) {
  var display = true;
  var LogItemsDiv = document.getElementById(LogItemsDivID);
  try {
    display = LogItemsDiv.style.display != "none";
  }
  catch (exc) { };

  if (display) {
    LogItemsDiv.style.display = "none";
    link.innerHTML = "Zobrazit detail";
  }
  else {
    LogItemsDiv.style.display = "block";
    link.innerHTML = "Skrýt detail";
  }
  return false;

}

//----------------------------------------------------------------------------

function ArrayExtend(arr) {
  if (arr.IndexOf == undefined) arr.IndexOf = IndexOf;
  if (arr.Contains == undefined) arr.Contains = Contains;
  if (arr.Remove == undefined) arr.Remove = Remove;
  return arr;
}
function Contains(item) {
  for (var i in this) {
    if (this[i] == item)
      return true;
  }
  return false;
}
function IndexOf(item) {
  for (var i in this) {
    if (this[i] == item)
      return i;
  }
  return -1;
}
function Remove(item) {
  var i = this.IndexOf(item);
  if (i > -1) {
    this.splice(i, 1);
    return true;
  }
  return false;
}