I created my own UserControl for logging a user on umbraco. Everything works fine, but do not work requireFieldValidator to making some fields. I put the controls on the client side of nell'aspx UserControl. Like this:

           <tr>
                            <td align="right">
                                <asp:Label ID="Label2" runat="server" AssociatedControlID="">
                                    Nome:
                                </asp:Label>
                            </td> 
                            <td>
                                <asp:TextBox ID="FirstName" Width="100px" runat="server"></asp:TextBox>
                                <asp:RequiredFieldValidator ID="RequiredFieldValidator3" runat="server" ControlToValidate="FirstName"
                                        ErrorMessage="Name is required." ToolTip="Name is required." ValidationGroup="CreateUserWizard1">*</asp:RequiredFieldValidator>
                            </td>
                        </tr>

Why not work? We must add a server-side control?

Thank you very much

Regards.

G.