How do I test my session-expiry code with VS2010

I have a problem on a page if the session expires. I think I can solve the problem with code that tests for a new session: -

        Dim NewSession As Boolean
        Dim httpApplication As New HttpApplication
        If httpApplication.Session.IsNewSession = True Then
            NewSession = True
        Else
            NewSession = False
        End If

        If Not Page.IsPostBack OrElse NewSession = True Then
              '   do first time code .....

This should execute my first-time code when the session has expired, as well as a genuine Not Postback.

How do I test this with Visual Studio? I read somewhere that VS debugger sessions don't expire, so unless I use the production environment for testing (obviously not a good idea) I can't just start a test and wait 20 minutes.

Thank you, Robert.

Re: How do I test my session-expiry code with VS2010

Correction, my code doesn't work. The statement
If httpApplication.Session.IsNewSession = True Then ...
thows an error:

Session state is not available in the current context

Re: How do I test my session-expiry code with VS2010

This worked.

        Dim NewSession As Boolean = False
        If Not Page.IsPostBack Then
            Session("Table_aspx_session") = "Exists"
        ElseIf IsNothing(Session("Table_aspx_session")) Then
            NewSession = True '   It must have timed out
        End If

It was safe enough, so I tested in on the production site. The name of the session variable, "Table_aspx_session" ensures that it is unique to this page which is table.aspx.