protected void btn_chamnhuanbut_click(object sender, EventArgs e)
 {
     foreach (DataGridItem m_Item in DataGrid_tinbaiAnh.Items)
     {
         CheckBox chk_Select = (CheckBox)m_Item.FindControl("optSelect");
         double   id         = 0;
         if (chk_Select != null && chk_Select.Checked)
         {
             id = double.Parse(DataGrid_tinbaiAnh.DataKeys[int.Parse(m_Item.ItemIndex.ToString())].ToString());
             string    sql         = "select Thanhtoan from T_Anh where Ma_Anh=" + id;
             UltilFunc ulti        = new UltilFunc();
             DataTable dtthanhtoan = ulti.ExecSqlDataSet(sql).Tables[0];
             bool      check       = false;
             if (dtthanhtoan.Rows[0]["Thanhtoan"].ToString() != DBNull.Value.ToString())
             {
                 check = (bool)dtthanhtoan.Rows[0]["Thanhtoan"];
             }
             if (check)
             {
                 Daltinbai.Sp_UpdateThanhToanNhuanButAnh(id, false, DateTime.Now, _user.UserID);
             }
             else
             {
                 Daltinbai.Sp_UpdateThanhToanNhuanButAnh(id, true, DateTime.Now, _user.UserID);
             }
         }
     }
     LoadData();
 }