asp:createuserwizard button click and asp:RequiredFieldValidator for other text box control - not working

see my  asp:createuserwizard placed in a page,
<asp:createuserwizard runat="server" Id="createuserwizard1" MembershipProvider="SqlProvider"  

                       name="createuserwizard1" style="" oncreatinguser="Createuserwizard1_CreatingUser"

                       OnCreatedUser="CreateUserWizard1_CreatedUser" TextBoxStyle-Width="150"

                       CompleteSuccessTextStyle-ForeColor="Azure" DisableCreatedUser="true"  

              ...