Private Sub ComboBox1_SelectedIndexChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ComboBox1.SelectedIndexChanged
        Dim venditore As String
        venditore = ComboBox1.Text

        sql = "SELECT da,a,utente FROM agenda WHERE  utente  = '" & venditore & "'"
        Dim dataadapter As New SqlDataAdapter(sql, cnn)
        Dim ds As New DataSet()
        Dim dt As New DataTable
        cnn.Open()
        dataadapter.Fill(ds, "agenda")

        Dim dr As DataRow

        For Each dr In ds.Tables("agenda").Rows
            Dim app As New Appointment()

            app.StartDate = dr("da")
            app.EndDate = dr("a")
            app.Subject = "Appuntamento del " & app.StartDate

            listaAppuntamenti.Add(app)
            DayView1.Invalidate()
        Next

        cnn.Close()