<asp:SqlDataSource ID="SqlImballi" runat="server" ConnectionString="<%$ ConnectionStrings:MyConnectionString %>" 
        SelectCommand="SELECT * FROM [ArtImballi] WHERE [articolo] = @articolo ORDER BY [Imballo]"
       onselecting="SqlImballi_Selecting" > 
        <SelectParameters>
            <asp:Parameter Name="articolo" Type="String" />
        </SelectParameters>
    </asp:SqlDataSource>