public function store(Request $request)
 {
     $this->store_validation_rules($request);
     $date_open = $this->saved_date_format($request->input('date_open'));
     $request->merge(array('date_open' => $date_open));
     $office = $request->input();
     Office::create($office);
     Session::flash('flash_message', 'Data berhasil ditambahkan!');
     return redirect('master/offices');
 }