online users calculation

Question

This line in my aspx page gives exception

<%=Application("OnlineVisitors").ToString()%>

 

below are the global.asax code

Sub Session_End(ByVal sender As Object, ByVal e As EventArgs)

Application.Lock()

Application("OnlineVisitors") = (CType(Application("OnlineVisitors"), Integer) - 1)

Application.UnLock()

End Sub

 

Sub Session_Start(ByVal sender As Object, ByVal e As EventArgs)

If Session("LoggedInUserId") Is Nothing Then Response.Redirect("Login.aspx", True)

Application.Lock()

' Application("OnlineVisitors") = (CType(Application("OnlineVisitors"), Integer) + 1)

Application("OnlineVisitors") = (CType(Application("OnlineVisitors"), Integer) + 1)

Application.UnLock()

'If Session("LoggedInUserId") IsNot Nothing Then

' GetDays()

'End If

' AutoChecked()

End Sub

 

Sub Application_Start(ByVal sender As Object, ByVal e As EventArgs)

RegisterRoutes(RouteTable.Routes)

Application("OnlineVisitors") = 0

' Fires when the application is started

Dim whenTaskLastRan As DateTime

whenTaskLastRan = DateTime.Now

Dim D2 As DateTime = DateTime.Now()

End Sub