I have a Grid view which I attached with dtasource ddSource1.  I have a
column in it "Roles" Which I converted as a Template field and create a
dropdown list and attached to another datasource ddSource2
which is from another data table.  but it is not working.

<asp:TemplateField HeaderText="Roles" SortExpression="Roles">
                   <EditItemTemplate>
                       <asp:Label ID="Label1" runat="server" Text='<%#
Eval("Roles") %>'></asp:Label><br />
                       <asp:DropDownList ID="DropDownList1" runat="server"
DataSourceID="ObjectDataSource22"
                           DataTextField="RoleName"
DataValueField="RoleName" SelectedValue='<%# Bind("RoleName") %>'>
                       </asp:DropDownList>
                       <br />
                   </EditItemTemplate>
                   <ItemTemplate>
                       <asp:Label ID="Label1" runat="server" Text='<%#
Bind("Roles") %>'></asp:Label>
                   </ItemTemplate>
               </asp:TemplateField>