Look at ASP.NET Files for the current ASP Scripts.
Look at the Introduction to Server Side Tracking before you start, and look at the parameters you can pass.
The WhosOn tracking code is added to the page load event of the site that you are wanting to track.
If you are using a MasterPage, then this can go in the MasterPage's page load.
Imports clsWhosOn
Partial Class SiteMasterPage
Inherits System.Web.UI.MasterPage
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
Dim whoson As New clsWhosOn
whoson.WhosOnGatewayInternalIP = "145.245.123.33"
whoson.WhosOnGatewayPort = 8080
whoson.WhosOnDomain = "www.test.com"
whoson.WhosOnAuthenticationString = "AUTHSTRING"
If whoson.SendPageInfoToWhosOn Then
If whoson.Response.OperatorsOnLine > 0 Then
' code here for display when operators are online
Else
' code here for display when operators are offline
End If
Else
' code for when tracking fails
End If
End Sub
End Class