private void brThem_ItemClick(object sender, RoutedEventArgs e)
 {
     this.Close();
     frmnhapdiaban frm = new frmnhapdiaban(false);
     frm.Show();
 }
 private void brSua_ItemClick(object sender, RoutedEventArgs e)
 {
     if (gridControl1.GetFocusedRow() != null)
     {
         frmnhapdiaban frm = new frmnhapdiaban(true);
         frm.txtmanv.Text = gridControl1.GetFocusedRowCellValue(ma_tuyen).ToString().Trim();
         frm.txtten.Text = gridControl1.GetFocusedRowCellValue(ten_tuyen).ToString().Trim();
         frm.checkEdit1.IsChecked = App.kythuat;
         this.Close(); 
         frm.Show();
     }
     else
         MessageBox.Show("Chưa chọn nhân viên cần sửa !");
 }