public function showAllJob($username){
    $this->db->order_by('id', 'desc');
    $this->db->like('assign_to', $username);
      $this->db->or_like('assign_by', $username);
    $query = $this->db->get('job_card');
    if($query->num_rows() > 0){
      return $query->result();
    }else{
      return false;
    }
  }