jQuery Grid Plugin - jqGrid

Hello,

Could someone please explain how to use the dataUrl in conjunction with the filterToolbar. My aim is to get a dropdown box on the filter toolbar which is dynamically loaded from an ajax request. This is fine for editoptions{} and pulls the data correctly.

The problem is that the filter toolbar field always displays a normal textbox. However if i used searchoptions {value:... } then it is fine. It just doesnt seem to work with dataUrl. Am i missing something please? Is this a bug in the system as i think i have followed documentation thoroughly. Any guidance will be appreciated. Thank you.

An example column in colmodel is this:

The Column:

{name:"category_id_link",index:"c.id",editable:true,edittype:"select",width:140,sortable:false,search:true, editoptions:{
    dataUrl:"jqGrid/actions/selectbox/sb_menu_categories.php",
    stype:'select',
    style:'width:95%',
    surl:"jqGrid/actions/selectbox/sb_menu_categories.php",
    searchoptions:{
        dataUrl:"jqGrid/actions/selectbox/sb_menu_categories.php"
    }
}},

The Pager:

$("#menugridlist").jqGrid('navGrid','#menugridpager', {search:false}, //options
    {height:'auto',width:'auto',reloadAfterSubmit:false, recreateForm: true}, // edit options
    {height:'auto',width:'auto',reloadAfterSubmit:false, recreateForm: true}, // add options
    {reloadAfterSubmit:false}, // del options
    {jqModal:false}, // search options
    {height:250,jqModal:false,closeOnEscape:true} // view options
);

The Filter Toolbar:

$("#menugridlist").jqGrid('filterToolbar',{stringResult: true,searchOnEnter : false});