ciao,
è la prima ovlta che utilizzo i codebehind, sto provando del codice che funzionava perfettamente prima.

nella mia pagina.aspx includo il codice cosi:
<%@ Page Language="vb" AutoEventWireup="false" Codebehind="login.aspx.vb" Inherits="laspiaggetta.ViewStateInSessionVar"%>

nel file login.aspx.vb ho questo:
codice:
Imports System.Data.OleDb
Imports System.Data


Public Class ViewStateInSessionVar
    Inherits System.Web.UI.Page
    Protected WithEvents Label1, Label2, Errore As System.Web.UI.WebControls.Label
    Protected WithEvents Button1 As System.Web.UI.WebControls.Button
    Protected WithEvents Nome, Pwd As System.Web.UI.WebControls.TextBox

    Sub Login(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button1.Click
        Dim ObjDatabase As New laspiaggetta.TYASPNET.database()

        ObjDatabase.ConnectionString = "provider=Microsoft.Jet.OLEDB.4.0; data source=" & Server.MapPath("../mdb-database/spaiggetta-db.mdb")

        Dim objReader As OleDbDataReader
        objReader = ObjDatabase.SelectSQL("SELECT id FROM Admin WHERE Nome='" & ObjDatabase.Controlla_Stringa(Nome.Text) & "' AND Pwd='" & ObjDatabase.Controlla_Stringa(Pwd.Text) & "' ")

        If Not objReader Is Nothing Then
            Session("Admin") = "ok"
            Response.Redirect("index.aspx")
        Else
            Errore.Visible = True
            Errore.Text = "ERRORE"
        End If
        objReader.Close()
    End Sub

End Class
mi da errore qui:
objReader.Close()

Object reference not set to an instance of an object.
Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

Exception Details: System.NullReferenceException: Object reference not set to an instance of an object.


che vuol dire?