@Override
public boolean onOptionsItemSelected(MenuItem item) {
 if (item.getItemId() == R.id.app) {
  Toast.makeText(MainActivity.this, "About", Toast.LENGTH_SHORT).show();
  return true;
 } else if (item.getItemId() == R.id.exit) {
  Toast.makeText(MainActivity.this, "Exit", Toast.LENGTH_SHORT).show();
  return true;
 } else if (item.getItemId() == R.id.call_admin) {
  Toast.makeText(MainActivity.this, "01784067744", Toast.LENGTH_SHORT).show();
  return true;
 }
 return super.onOptionsItemSelected(item);
}