function nocontextmenu() {
  event.cancelBubble = true, event.returnValue = false;

  return false;
} 

function norightclick(e) {
  if (window.Event) {
    if (e.which == 2 || e.which == 3) return false;
  }
  else if (event.button == 2 || event.button == 3) {
    event.cancelBubble = true, event.returnValue = false;
    return false;
  }
}