ASP .NET Newbee - Stupid Question

[<ABX]

<%@ Import Namespace="System.IO" %>
<script language="VB" runat="server">
  Sub Page_Load(sender as Object, e as EventArgs)
    Dim dirInfo as New DirectoryInfo(Server.MapPath("/dir1/dir2/"))
    
    articleList.DataSource = dirInfo.GetFiles("*.*")
    articleList.DataBind()
  End Sub
</script>

<asp:DataGrid runat="server" id="articleList" Font-Name="Verdana"
    AutoGenerateColumns="False" AlternatingItemStyle-BackColor="#eeeeee"
    HeaderStyle-BackColor="Navy" HeaderStyle-ForeColor="White"
    HeaderStyle-Font-Size="15pt" HeaderStyle-Font-Bold="True">
  <Columns>
    <asp:HyperLinkColumn DataNavigateUrlField="Name" DataTextField="Name" 
           HeaderText="File Name" />
    <asp:BoundColumn DataField="LastWriteTime" HeaderText="Last Write Time"
        ItemStyle-HorizontalAlign="Center" DataFormatString="{0:d}" />
    <asp:BoundColumn DataField="Length" HeaderText="File Size"
		ItemStyle-HorizontalAlign="Right" 
		DataFormatString="{0:#,### bytes}" />
  </Columns>
</asp:DataGrid>

this code works; to an extent. It displays all the files in the directory and links them but it links them to "http://localhost/[filename], but the files are int "http://localhost/dir1/dir2/[filename]"

how do i fix this problem????

[<ABX]

Well i created a Virtual Directory and put my aspx page in there and linked it from my main page so i solved my problem.

Is there any way i can get it to only show *.avi , *.wmv , *.mpg and how do i get the links to download by default instead of playing in the browser.