<asp:CreateUserWizardStep ID="CreateUserWizardStep1" runat="server">
                <ContentTemplate>
                    <table>
                        <tr><td>
                                <asp:TextBox ID="UserName" CssClass="textboxStyle" runat="server" 
                                    ToolTip="User Name"></asp:TextBox>
                                <asp:RequiredFieldValidator ID="UserNameRequired" runat="server" 
                                    ControlToValidate="UserName" ErrorMessage="User Name is required." 
                                    ToolTip="User Name is required." ValidationGroup="CreateUserWizard1">*</asp:RequiredFieldValidator>
                        </td></tr>
                        <tr><td>
                                <asp:TextBox ID="Password" CssClass="textboxStyle" runat="server" 
                                    TextMode="Password" ToolTip="Password"></asp:TextBox>
                                <asp:RequiredFieldValidator ID="PasswordRequired" runat="server" 
                                    ControlToValidate="Password" ErrorMessage="Password is required." 
                                    ToolTip="Password is required." ValidationGroup="CreateUserWizard1">*</asp:RequiredFieldValidator>
                         </td></tr>
                        <tr><td>
                                <asp:TextBox ID="ConfirmPassword" CssClass="textboxStyle" runat="server" 
                                    TextMode="Password" ToolTip="Confirm Password"></asp:TextBox>
                                <asp:RequiredFieldValidator ID="ConfirmPasswordRequired" runat="server" 
                                    ControlToValidate="ConfirmPassword" 
                                    ErrorMessage="Confirm Password is required." 
                                    ToolTip="Confirm Password is required." ValidationGroup="CreateUserWizard1">*</asp:RequiredFieldValidator>
                            </td></tr>
                        <tr><td>
                                <asp:TextBox ID="Email" CssClass="textboxStyle" runat="server" 
                                    ToolTip="[email protected]"></asp:TextBox>
                                <asp:RequiredFieldValidator ID="EmailRequired" runat="server" 
                                    ControlToValidate="Email" ErrorMessage="E-mail is required." 
                                    ToolTip="E-mail is required." ValidationGroup="CreateUserWizard1">*</asp:RequiredFieldValidator>
                       </td></tr>
                       <tr><td>
                       <p>Please identify yourself in one of the following:</p>
                           <asp:DropDownList ID="DropDownList1" runat="server">
                               <asp:ListItem>Student</asp:ListItem>
                               <asp:ListItem>Principal</asp:ListItem>
                               <asp:ListItem>Vice Principal</asp:ListItem>
                               <asp:ListItem>Teacher</asp:ListItem>
                               <asp:ListItem>Clerkial Staff</asp:ListItem>
                               <asp:ListItem>Other Staff</asp:ListItem>
                           </asp:DropDownList>
                                <asp:RequiredFieldValidator ID="identityRequired" runat="server" 
                                    ControlToValidate="DropDownList1" ErrorMessage="Identification in one of the categories is required." 
                                    ToolTip="Identification is required." ValidationGroup="CreateUserWizard1">*</asp:RequiredFieldValidator>
                       
                       </td></tr> 



                        <tr>
                            <td align="center">
                                <asp:CompareValidator ID="PasswordCompare" runat="server" 
                                    ControlToCompare="Password" ControlToValidate="ConfirmPassword" 
                                    Display="Dynamic" 
                                    ErrorMessage="The Password and Confirmation Password must match." 
                                    ValidationGroup="CreateUserWizard1"></asp:CompareValidator>
                            </td>
                        </tr>
                        <tr>
                            <td align="center" style="color:Red;">
                                <asp:Literal ID="ErrorMessage" runat="server" EnableViewState="False"></asp:Literal>
                            </td>
                        </tr>
                    </table>
                </ContentTemplate>
                <CustomNavigationTemplate>
                    <table border="0" cellspacing="5" style="width:100%;height:100%;">
                        <tr align="right">
                            <td align="left" colspan="0">
                                <asp:Button ID="StepNextButton" CssClass="buttonStyle" runat="server" CommandName="MoveNext" 
                                    Text="Create User" ValidationGroup="CreateUserWizard1" />
                            </td>
                        </tr>
                    </table>
                </CustomNavigationTemplate>
            </asp:CreateUserWizardStep>

protected void CreateUserWizard1_CreatedUser(object sender, EventArgs e)
{
        TextBox Category = DropDownList1.SelectedValue;

        // Get the UserId of the just-added user
        MembershipUser newUser = Membership.GetUser(CreateUserWizard1.UserName);
        Guid newUserId = (Guid)newUser.ProviderUserKey;

        // Insert a new record into UserProfiles
        string connectionString =
                ConfigurationManager.ConnectionStrings["ConnectionString"].ConnectionString;
        string insertSql = "INSERT INTO UserDetails(UserId, FirstName, MiddleName, LastName, HomeTown, Category) VALUES(@UserId, @FirstName, @MiddleNAme, @LastName, @HomeTown, @Category)";

        using (SqlConnection myConnection = new SqlConnection(connectionString))
        {
            myConnection.Open();
            SqlCommand myCommand = new SqlCommand(insertSql, myConnection);
            myCommand.Parameters.AddWithValue("@UserId", newUserId);
            myCommand.Parameters.AddWithValue("@FirstName", DBNull.Value);
            myCommand.Parameters.AddWithValue("@MiddleName", DBNull.Value);
            myCommand.Parameters.AddWithValue("@LastName", DBNull.Value);
            myCommand.Parameters.AddWithValue("@HomeTown", DBNull.Value);
            myCommand.Parameters.AddWithValue("@Category", Category.Text.Trim());
            myCommand.ExecuteNonQuery();
            myConnection.Close();
        }

}

DropDownList category = (DropDownList)CreateUserWizard1.CreateUserStep.ContentTemplateContainer.FindControl("DropDownList1");