Splitter collapse and expand commands not working nor recognized by jQuery/Firebug

[Jermaine]

My solution uses a splitbar to hide a upload button in the lower half of the pane and a listbox and a dropdownlistbox in the upper half of the same pane.  The splitbar should be collapsed upon page load, hiding the upload button.  What is the command for this?  I can place the command in the Page_load of the web page if I knew it.  Also, the splitbar should move down, collapse, to hide the upload button when the dropdownlistbox option is changed.  The splitbar should move up, expand, when the user completes the selection process by choosing a option in the listbox.  None of the animations are working. 

The control does work when coded within the vb codebehind but I am required to have it operate on the client side using jQuery.  In Firefox v21.0, Firebug gives me the following error:

 

TypeError: splitter.expand is not a function.  

I'm using Telerik RadControls for ASP.NET Ajax version 2013.1.220.40.  Thanks.

    $(function () {

        $('#<%= dropdwn.ClientID %>').change(function (e) {

            B_SelectedIndexChanged();

            resizePane(false)
            e.preventDefault();
        });

        $('#<%= Listbox.ClientID %>').change(function (e) {

            O_SelectedItemChanged();

            resizePane(true)
            e.preventDefault();

        });

});

function resizePane(source) {

        var splitter = $("#<%= HideUploadRadsplitbar.ClientID %>");
        var pane = $("#<%= FileUploadRadpane.ClientID %>");

        if (source = true) {

                splitter.expand();

        } else {

            pane.collapse();

        }
    }