public function postEditTask()
 {
     $validator = Taskcard::validate(Input::all());
     if ($validator->fails()) {
         return Response::json($validator);
     }
     $task_id = Input::get('id');
     try {
         $task = Taskcard::findOrFail($task_id);
         $task->title = Input::get('title');
         $task->content = Input::get('content');
         if (!is_null(Input::get('status'))) {
             $task->status = Input::get('status');
         } else {
             $task->status = "Todo";
         }
         if (!is_null(Input::get('start'))) {
             $task->start = Input::get('start');
         }
         if (!is_null(Input::get('end'))) {
             $task->end = Input::get('end');
         }
         if (strtotime($task->start) >= strtotime($task->end)) {
             return Response::json(array('error' => 'Invalid time'));
         }
         $task->save();
         return Response::json($task);
     } catch (Exception $e) {
         return Response::json(404);
     }
 }