public function addHistory($id, $leave, $days, $action, $leaveDays, $details, $added)
 {
     $data = array('employee_id' => $id, 'leave_type' => $leave, 'leave_left' => $days, 'action' => $action . ' ' . $added . ' day/s Leave', 'updated_leave' => $leaveDays, 'details' => $details);
     Leave_history_model::create($data);
 }