[flexcoders] grouping collection for combobox

[kpjj31]

I am trying to apply a grouping collection to my combobox. The array collection 
is a result of a remote object. When I use the grouping colelction as a 
dataProvide, I get not results.


<mx:GroupingCollection id="jobsgroup" source="{departmentlist}"> 
          
<mx:Grouping> 
<mx:GroupingField name="JOBTITLE"/> 
</mx:Grouping> 
       
</mx:GroupingCollection>

<mx:ComboBox id="jobs_cb" x="616" y="24" width="364" 
dataProvider="{jobsgroup.getData(jobsgroup.getRoot())}" labelField="GroupLabel"/