debug vb.net 2010 web forms application

In an asp.net 2010 web form application that that is written in visual basic, the following is contained in a gridview control:
</HeaderTemplate>   <ItemTemplate>    <asp:CheckBox id="cbBuildLetter"  Enabled="true" runat="server" onclick="cbReadClick(this)"  />                          </ItemTemplate>   </asp:TemplateField>   <asp:TemplateField HeaderText="No Letter" ItemStyle-HorizontalAlign="Center" ItemStyle-Width="5%" ItemStyle-CssClass="ui-widget-content" >   <ItemTemplate>   <asp:CheckBox id="cbNoLetter"  runat="server" onclick="cbReadClick(this)"  />                ...