public function postRules(Request $request)
 {
     $user = Auth::user();
     if ($user->is('admin')) {
         $ids = $request->input('ids');
         $expressions = $request->input('expressions');
         for ($i = 0; $i < count($ids); $i++) {
             $id = $ids[$i];
             $rule = Rule::find($id);
             if ($request->has('delete_' . $id)) {
                 $rule->delete();
             } else {
                 $rule->expression = $expressions[$i];
                 $rule->save();
             }
         }
         $new = $request->input('newrule');
         if (empty($new) == false) {
             $rule = new Rule();
             $rule->expression = $new;
             $rule->save();
         }
         return redirect(url('admin/rules'));
     } else {
         abort(403);
     }
 }