Data Management Service

Hello, I urgently need your help.

I have to invoke a Java DAO from LiveCycle DataService. I configured a Data Management Service that works correctly. When I invoke the method, however, the ArrayCollection is not populated immediately, but is populated after running all the actionscript code. I need to use the data from the server in successive method calls. eg:

                                        public function initApp():void {

        var collectionTest:ArrayCollection = new ArrayCollection();

        var ds:DataService = new DataService("Product");

                                                       ds.autoSyncEnabled = true;

                                                       ds.autoCommit = false;

                                                       var token:AsyncToken = ds.fill(collectionTest);

        var description = this.getProductDescription(collectionTest.getItemIndex(0));

        var ds2:DataService = new DataService("UpdateProdotto");

        ..........

        var collectionTest2:ArrayCollection = new ArrayCollection();       

        ds2.fill(collectionTest2, description);

        .........

}

How can I do that?

thank you very much.