multiple comboboxes problems

[matt]

hello,

ive seen this example for multiple comboboxes that interact w/ each other:

http://demos.telerik.com/ASPNET/Prometheus/Combobox/Examples/Functionality/MultipleComboBoxes/DefaultCS.aspx

and now im trying to get its technique to work w/ my own comboboxes. i am able to do so in  a naked .ASPX page. it works as expected, cool.

but when using MasterPages, im having a problem w/ this line:

var rcbVehicleModels = $find("rcbVehicleModels");

...this comes back NULL, and breaks the rest of the technique.

is there something i have to do differently when working w/ MasterPages? perhaps as in a parent element ID to to the $find() method?

thanks!
matt


my .ASPX code:

<asp:Content ID="Content1" ContentPlaceHolderID="phContent" runat="server">

    <table width="100%">
        <tr>
            <td width="50%">
                <span class="formLabel">Make:</span><br />

                <Telerik:RadComboBox ID="rcbVehicleMakes"
                    DataValueField="VehicleMakeTypeID"
                    DataTextField="Description"
                    Width="150"
                    DropDownWidth="220"
                    AllowCustomText="False"
                    MarkFirstMatch="true"
                    Skin="Gray"
                    OnClientSelectedIndexChanging="LoadModels"
                    runat="server"/>

            </td>
            <td width="50%">
                <span class="formLabel">Model:</span><br />

                <Telerik:RadComboBox ID="rcbVehicleModels"
                    DataValueField="VehicleModelTypeID"
                    DataTextField="Description"
                    Width="80"
                    DropDownWidth="125"
                    AllowCustomText="False"
                    MarkFirstMatch="true"
                    Skin="Gray"
                    OnItemsRequested="rcbVehicleModels_ItemsRequested"
                    OnClientItemsRequested="ItemsLoaded"
                    runat="server" />

            </td>
        </tr>
    </table>



    <script type="text/javascript">
        //called when VehicleMakes changes
        function LoadModels(combo, eventargs)
        {
            var item = eventargs.get_item();

            if (item.get_index() > 0) //Make selected, get Models
            {
                var rcbVehicleModels = $find("rcbVehicleModels");

               //alert(rcbVehicleModels); //returns NULL!

                rcbVehicleModels.set_text("Loading...");

                rcbVehicleModels.requestItems(item.get_value(), false);
            }
            else //empty item selected, reset Models
            {
                rcbVehicleModels.set_text(" ");
                rcbVehicleModels.clearItems();
            }
        }

        //called when VehicleModels loads its items
        function ItemsLoaded(combo, eventarqs)
        {
            if (combo.get_items().get_count() > 0)
            {
                combo.set_text(combo.get_items().getItem(0).get_text());
                combo.get_items().getItem(0).highlight();
            }

            combo.showDropDown();
        }
    </script>

</asp:Content>

[matt]

got it -- when in a naked .ASPX page, the html clientside ID of the RadComboBox is the same as the server-side ID. but when in a content page, its prefixed w/ other junk, so you have to retrieve its clientside ID like so:

var rcbVehicleModels = $find('<%= rcbVehicleModels.ClientID %>');