private void AddStaff()
 {
     try
     {
         FrmInforTabStaff.isAdd = true;
         FrmInforTabStaff frm = new FrmInforTabStaff();
         frm.StartPosition = FormStartPosition.CenterScreen;
         frm.ShowDialog();
         LoadTabStaff();
     }
     catch (Exception ex)
     {
         MessageBox.Show(ex.Message);
     }
 }
 private void EditStaff()
 {
     try
     {
         if (row < 0)
         {
             throw new Exception("Chọn nhân viên cần sửa");
         }
         FrmInforTabStaff.isAdd   = false;
         FrmInforTabStaff.idStaff = Int32.Parse(dgvStaff.Rows[row].Cells[0].Value.ToString());
         FrmInforTabStaff frm = new FrmInforTabStaff();
         frm.StartPosition = FormStartPosition.CenterScreen;
         frm.ShowDialog();
         LoadTabStaff();
     }
     catch (Exception ex)
     {
         MessageBox.Show(ex.Message);
     }
 }