<asp:DropDownList ID="ddlRegione" runat="server" 
            DataSourceID="sdsRegione" DataTextField="Regione" 
            DataValueField="idRegione" Width="200px" AutoPostBack="True">
        </asp:DropDownList>
        <asp:SqlDataSource ID="sdsRegione" runat="server" 
            ConnectionString="<%$ ConnectionStrings:dbIMMOBILIConnectionString1 %>" 
            SelectCommand="SELECT [idRegione], [Regione] FROM [dbREGIONE]">
        </asp:SqlDataSource>
        <asp:DropDownList ID="ddlProvincia" runat="server" Width="200px" 
            AutoPostBack="True" DataSourceID="sdsProvincia" DataTextField="Provincia" 
            DataValueField="idProvincia">
        </asp:DropDownList>
        <asp:SqlDataSource ID="sdsProvincia" runat="server" 
            ConnectionString="<%$ ConnectionStrings:dbIMMOBILIConnectionString1 %>" 
            SelectCommand="SELECT [idProvincia], [Provincia] FROM [dbPROVINCIA] WHERE ([idRegione] = @idRegione)">
            <SelectParameters>
                <asp:ControlParameter ControlID="ddlRegione" Name="idRegione" 
                    PropertyName="SelectedValue" Type="Int32" />
            </SelectParameters>
        </asp:SqlDataSource>
        <asp:DropDownList ID="ddlComune" runat="server" AutoPostBack="True" 
            DataSourceID="sdsComune" DataTextField="Comune" DataValueField="idComune" 
            Width="200px">
        </asp:DropDownList>
        <asp:SqlDataSource ID="sdsComune" runat="server" 
            ConnectionString="<%$ ConnectionStrings:dbIMMOBILIConnectionString1 %>" 
            SelectCommand="SELECT [idComune], [Comune] FROM [dbCOMUNE] WHERE ([idProvincia] = @idProvincia)">
            <SelectParameters>
                <asp:ControlParameter ControlID="ddlProvincia" Name="idProvincia" 
                    PropertyName="SelectedValue" Type="Int32" />
            </SelectParameters>
        </asp:SqlDataSource>
        <asp:DropDownList ID="ddlOperazione" runat="server" AutoPostBack="True" 
        Width="200px" DataSourceID="sdsOperazione" DataTextField="Operazione" 
            DataValueField="idOperazione">
        </asp:DropDownList>
        <asp:SqlDataSource ID="sdsOperazione" runat="server" 
            ConnectionString="<%$ ConnectionStrings:dbIMMOBILIConnectionString1 %>" 
            SelectCommand="SELECT [idOperazione], [Operazione] FROM [OPERAZIONE]">
  </asp:SqlDataSource>
        <br />