Add the Domain filed to default Login control and using it with active directory

<asp:Login ID="LoginUser" runat="server" EnableViewState="false"
       RenderOuterTable="false" DisplayRememberMe="False">
       <LayoutTemplate>
           <table cellpadding="1" cellspacing="0" style="border-collapse:collapse;">
               <tr>
                   <td>
                       <table cellpadding="0">
                           <tr>
                               <td align="center" colspan="2">
                                   Log In</td>
                           </tr>
                           <tr>
                               <td align="right">
                                   <asp:Label ID="UserNameLabel" runat="server" AssociatedControlID="UserName">User Name:</asp:Label>
                               </td>
                               <td>
                                   <asp:TextBox ID="UserName" runat="server"></asp:TextBox>
                                   <asp:RequiredFieldValidator ID="UserNameRequired" runat="server"
                                       ControlToValidate="UserName" ErrorMessage="User Name is required."
                                       ToolTip="User Name is required." ValidationGroup="LoginUser">*</asp:RequiredFieldValidator>
                               </td>
                           </tr>
                           <tr>
                               <td align="right">
                                   <asp:Label ID="PasswordLabel" runat="server" AssociatedControlID="Password">Password:</asp:Label>
                               </td>
                               <td>
                                   <asp:TextBox ID="Password" runat="server" TextMode="Password"></asp:TextBox>
                                   <asp:RequiredFieldValidator ID="PasswordRequired" runat="server"
                                       ControlToValidate="Password" ErrorMessage="Password is required."
                                       ToolTip="Password is required." ValidationGroup="LoginUser">*</asp:RequiredFieldValidator>
                               </td>
                           </tr>
                                                       <tr>
                               <td align="right">
                                   <asp:Label ID="DomainLabel" runat="server" AssociatedControlID="Domain">Domain:</asp:Label>
                               </td>
                               <td>
                                   <asp:TextBox ID="Domain" runat="server"></asp:TextBox>
                                   <asp:RequiredFieldValidator ID="RequiredFieldValidator1" runat="server"
                                       ControlToValidate="Domain" ErrorMessage="Domain is required."
                                       ToolTip="Domain is required." ValidationGroup="LoginUser">*</asp:RequiredFieldValidator>
                               </td>
                           </tr>
                           <tr>
                               <td align="center" colspan="2" style="color:Red;">
                                   <asp:Literal ID="FailureText" runat="server" EnableViewState="False"></asp:Literal>
                               </td>
                           </tr>
                           <tr>
                               <td align="right" colspan="2">
                                   <asp:Button ID="LoginButton" runat="server" CommandName="Login" Text="Log In"
                                       ValidationGroup="LoginUser" />
                               </td>
                           </tr>
                       </table>
                   </td>
               </tr>
           </table>
       </LayoutTemplate>
   </asp:Login>