I have created a menu ,but the sub menu are not showing

<asp:Menu ID="Menu1" runat="server" 
                                                Height="21px" Font-Overline="False" Font-Strikeout="False" 
                                                Font-Underline="False" Width="54px" Orientation="Horizontal" 
                                    style="margin-left: 0px" ForeColor="White" Font-Size="Small" 
                                    Font-Names="Times New Roman">
                                                <StaticMenuStyle BorderStyle="None" />
                                                <StaticMenuItemStyle 
                                                    BackColor="#FF0066" BorderColor="White" 
                                                    BorderWidth="1px" />
                                                <DynamicHoverStyle BorderStyle="Dotted" 
                                                    BorderWidth="2px" />
                                                <Items>
                                                    <asp:MenuItem Text="    &nbsp; Home &nbsp;  " Value="HOME" NavigateUrl="~/Home.aspx"></asp:MenuItem>
                                                    <asp:MenuItem Text="      &nbsp; Contact Us &nbsp;  " Value="CONTACT US" 
                                                        NavigateUrl="~/ContactUs.aspx"></asp:MenuItem>
                                                    <asp:MenuItem Text="     &nbsp; Corporate &nbsp; " Value="CORPORATE" NavigateUrl="#">
                                                        <asp:MenuItem NavigateUrl="~/ProfilrTally.aspx" Text=" &nbsp; PROFILE &nbsp;" 
                                                            Value="PROFILE">
                                                        </asp:MenuItem>
                                                        <asp:MenuItem NavigateUrl="~/AboutUs.aspx" Text="  &nbsp; ABOUT US &nbsp;" Value="ABOUT US">
                                                        </asp:MenuItem>
                                                        <asp:MenuItem NavigateUrl="~/Mission.aspx" Text="&nbsp; MISSION &nbsp;" Value="MISSION">
                                                        </asp:MenuItem>
                                                    </asp:MenuItem>
                                                    <asp:MenuItem Text="   &nbsp; Products &nbsp; " Value="PRODUCTS" 
                                                        NavigateUrl="~/Products.aspx"></asp:MenuItem>
                                                    <asp:MenuItem Text="   &nbsp; Services &nbsp; " Value="SERVICES" 
                                                        NavigateUrl="~/Services.aspx"></asp:MenuItem>
                                                    <asp:MenuItem Text="    &nbsp; Clients  &nbsp;  " Value="CLIENTS" 
                                                        NavigateUrl="~/Client.aspx"></asp:MenuItem>
                                                </Items>
                                            </asp:Menu>