Display Horizontal Menus in ASP.Net Menu Control using SiteMap

I am foolowing the article

http://www.aspsnippets.com/Articles/Using-ASPNet-Menu-control-with-example-in-C-and-VBNet.aspx

but I am not able to see my links horizontally

here is my site map file

<?xml version="1.0" encoding="utf-8"?>
<siteMap xmlns="http://schemas.microsoft.com/AspNet/SiteMap-File-1.0" >

<siteMapNode url="~/default.aspx"
			title="Home"
			description=""
			roles="*">

<siteMapNode url="~/Member/Default.aspx"
				title="Member Home"
				description="Home Page" ></siteMapNode>

	<siteMapNode title="My Biz"
				roles="MediaAdmin"
				url="javascript:;">
	<siteMapNode url="~/MediaAdmin/InsertDealer.aspx"
					title="Add New Dealer"
					description="" ></siteMapNode>
	<siteMapNode url="~/MediaAdmin/InsertDealer2.aspx"
					title="InsertDealer2"
					description="" ></siteMapNode>
	<siteMapNode url="~/MediaAdmin/DelaerSearch.aspx"
					title="Dealer Search"
					description="" ></siteMapNode>
	<siteMapNode url="~/MediaAdmin/Default.aspx"
					title="MediaAdmin"
					description="" ></siteMapNode>
	<siteMapNode url="~/MediaAdmin/ProductMediaUpdate.aspx"
					title="ProductMediaUpdate"
					description="" ></siteMapNode>

</siteMapNode>
</siteMapNode>
</siteMap>

The access to these links are controlled by membership provider.

Home is accessed by everyone. "Member Home" and MyBiz are accessed when the user is logged in.

The menu should have only Home displayed and when the user is logged in then it should displaym Home, MemberHome, MyBiz and sub links.

Here is the code for menu contol

<asp:Menu ID="HorizontalMenuId"  runat="server" 
      DataSourceID="SiteMapDataSource1" Orientation="Horizontal">
      <LevelMenuItemStyles>
      <asp:MenuItemStyle CssClass="main_menu" />
      <asp:MenuItemStyle CssClass="level_menu" />
      </LevelMenuItemStyles>
</asp:Menu>

Thanks