private void set_define_events()
{
this.Load += F150_dm_nhan_vien_Load;
//li lich nhan vien
m_cmd_them_nhan_vien.Click += m_cmd_them_nhan_vien_Click;
m_dat_ngay_sinh.ValueChanged += m_dat_ngay_sinh_ValueChanged;
m_cmd_insert.Click += m_cmd_insert_Click;
m_cmd_tra_cuu.Click += m_cmd_tra_cuu_Click;
}