Dim where as String = ""

            If ComboBoxPeriodoBolla.Text <> "Intero Anno" Then
                If where.Length > 0 Then where = where & " AND "
                where = where & "Month(R_DataDocumento) = " & (ComboBoxPeriodoBolla.SelectedIndex().ToString) & ""
            End If

            If ComboBoxFornitore.Text <> "Tutti i Fornitori" Then
                If where.Length > 0 Then where = where & " AND "
                where = where & "MovimentiMagazzino.ID_Fornitore = " & (ComboBoxFornitore.Text) & ""
            End If