Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs)

        
        cn = New OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0; Data Source=" & Server.MapPath("mdb-database/dati.mdb"))
        
        
        If Not IsPostBack Then
            cn.Open()
            
            cmd = New OleDbCommand("select * from Province ORDER BY Capoluogo", cn)
            Provincia.DataSource = cmd.ExecuteReader()
            Provincia.DataTextField = "Capoluogo"
            Provincia.DataValueField = "IDProvincia"
            Provincia.DataBind()
            Provincia.Dispose()
            
                dst = New DataSet
                dap = New OleDbDataAdapter("SELECT * FROM Utenti WHERE IDUtente=" & Session("IDUtente"), cn)
                dap.Fill(dst, "Utenti")
                With dst.Tables("Utenti").Rows(0)
                                        
                    Provincia.SelectedValue = .Item("IDProvincia")
                    cn.Close()
                    AggiornaComune(.Item("IDProvincia"))
                    Comune.SelectedValue = .Item("IDComune")
                   

            cn.Close()
        end if


   End Sub

Sub Provincia_Change(ByVal sender As Object, ByVal e As System.EventArgs) Handles Provincia.SelectedIndexChanged
        AggiornaComune(Provincia.SelectedValue)
    End Sub

Sub AggiornaComune(ByVal x As Integer)
        Comune.Enabled = True
        Comune.Items.Clear()

        cn.Open()
        cmd = New OleDbCommand("select * from QueryComuni WHERE IDProvincia=" & x & " ORDER BY Comune", cn)
        Comune.DataSource = cmd.ExecuteReader()
        Comune.DataTextField = "Comune"
        Comune.DataValueField = "IDComune"
        Comune.DataBind()
        Comune.Dispose()
        Comune.Enabled = True
        cn.Close()
    End Sub
    





    Protected Sub Conferma_Click(ByVal sender As Object, ByVal e As System.EventArgs)
        cn.Open()
        dst = New DataSet
        dap = New OleDbDataAdapter("SELECT * FROM Utenti WHERE email='" & fApici(Email.Text) & "'", cn)
        dap.Fill(dst, "Cuochi")
        
        
        If Cognome.Text = "" Then msg.Text = "Manca il (COGNOME)" : cn.Close() : Exit Sub
        If Nome.Text = "" Then msg.Text = "Manca il (NOME)" : cn.Close() : Exit Sub
        If Password.Text = "" Then Msg.Text = "Manca la (PASSWORD)" : cn.Close() : Exit Sub
        
        If Request("Tipo") <> "Modifica" Then
            If Email.Text = "" Then Msg.Text = "Manca la (E-MAIL)" : cn.Close() : Exit Sub
            
            If (dst.Tables("Cuochi").Rows.Count) = 1 Then
                Msg.Text = "email già esistente!"
                cn.Close()
                Exit Sub
            End If
            
            sql = "INSERT INTO Utenti (IDProvincia,IDComune) " & _
            "VALUES (" & _
            "" & Provincia.SelectedValue & "," & _
            "" & Comune.SelectedValue & ")"
           
            cmd = New OleDbCommand(sql, cn)
            cmd.ExecuteNonQuery()
            cn.Close()
            
              
    End Sub

<tr>
<td>Provincia:</td>
<td>
<asp:DropDownList ID="Provincia" runat="server"  Width="204"   
     AutoPostBack="true" onselectedIndexChanged="Provincia_Change" >
</asp:DropDownList>
</td>
</tr>
                
  
<tr>
<td>Città:</td>
<td>
<asp:DropDownList ID="Comune" runat="server" Width="204"  >
</asp:DropDownList>
</td>
</tr>

sql = "INSERT INTO Utenti (IDProvincia,IDComune) " & _
            "VALUES (" & _
            "" & Provincia.SelectedItem.Value & "," & _
            "" & Comune.SelectedItem.Value & ")"

If Not Page.IsPostBack Then
....
end if