ASP.Net/File Directory/DirectoryEntry

DirectoryEntry("LDAP://CN=Username, CN=users, DC=DomainName")

<%@ Page %>
<script Language="vb" runat="server">
Sub Page_Load(ByVal sender As System.Object, ByVal e As System.EventArgs)
    Dim User As System.DirectoryServices.DirectoryEntry
    Try
    User = New System.DirectoryServices.DirectoryEntry("LDAP://CN=Username, CN=users, DC=DomainName")
        Dim Value As String
        Value = User.Properties("HomeNumber").Item(0)
    Catch
        "Show error message
    Finally
        User.Close()
    End Try
End Sub
</script>

DirectoryEntry("LDAP://DomainName", Login, Password)

<%@ Page %>
<script Language="vb" runat="server">
Sub Page_Load(ByVal sender As System.Object, ByVal e As System.EventArgs)
    If Not ValidateUser("Login", "Password") Then
    End If
End Sub
Function ValidateUser(ByVal Login As String, ByVal Password As String) As Boolean
    Dim Entry As DirectoryEntry
    Try
    Entry = New DirectoryEntry("LDAP://DomainName", Login, Password)
        Dim Search As DirectorySearcher = New DirectorySearcher(Entry)
        Dim results As SearchResult = Search.FindOne
        Return True
    Catch
        Return False
    Finally
        Entry.Close()
    End Try
End Function
</script>

DirectoryServices.DirectoryEntry

<%@ Page %>
<script Language="vb" runat="server">
Sub Page_Load(ByVal sender As System.Object, ByVal e As System.EventArgs)
    Dim Entry As System.DirectoryServices.DirectoryEntry
    Try
    Entry = New System.DirectoryServices.DirectoryEntry("WinNT://DomainName")
    Catch
        "Error message
    Finally
        Entry.Close()
    End Try
End Sub
</script>