WebRequest - download files from directory without knowing name of file

[CodeMotion]

I have access to an internet directory and files will be placed in
this directory periodically. I am writing a service to poll that
directory and download the files for processing. I have figured out
how to download the files if I have the name of the file. However, I
will not know the names of these files that I need to download. So,
Is there a way to download a file from a directory in which you do not
know the name of the file?

I am currently using the HttpWebRequest/HttpWebResponse objects to do
this. Here is some code that accomplishes my task.
*************** *************** *************** *************** *********
Dim site As String =
"https://somedomain.com/somedirectory/somefilename.xm l"
Dim authuri As String = "https://somedomain.com"
Dim userName As String = "u"
Dim password As String = "p"
Dim domain As String = "www.somedomain .com"
Dim receipt As String = Nothing

'Prepare authentication header
Dim einfoCache As New CredentialCache ()
einfoCache.Add( New Uri(authuri), "Basic", New
NetworkCredenti al(userName, password))
einfoCache.Add( New Uri(authuri), "Digest", New
NetworkCredenti al(userName, password, domain))

Dim request As WebRequest = HttpWebRequest. Create(site)
With request
.Credentials = einfoCache
.PreAuthenticat e = False
.ContentType = "text/xml"
.Method = "GET"
End With

Dim response As WebResponse = request.GetResp onse()
Dim reader As StreamReader = New
StreamReader(re sponse.GetRespo nseStream(), System.Text.Enc oding.UTF8)
receipt = reader.ReadToEn d()
****Code Omitted From Here Down****
*************** *************** *************** *************** *********

The 'site' var is the problem child. I can download the file if I
know the name but I need to be able to find the name...then download
it. Any help will be greatly appreciated.

Thanks