How to control List Item with flash builder

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Flash

when i click button , new data was created . i want to focus or selected that new item .
How can i do that .
Here my code

<?xml version="1.0" encoding="utf-8"?>

<s:Application xmlns:fx="http://ns.adobe.com/mxml/2009"
               xmlns:s="library://ns.adobe.com/flex/spark"
               xmlns:mx="library://ns.adobe.com/flex/mx">
    <s:layout>
        <s:VerticalLayout/>
    </s:layout>

    <fx:Script>
        <![CDATA[
            // Add data item, and button, to the List.
            private function addFlexToDP():void {
                myBB.dataProvider.addItem("Flex");
                addFlex.enabled=false;

                // how to select or focus to new item created
            }

        ]]>
    </fx:Script>

    <s:List id="myBB">
        <mx:ArrayCollection>
            <fx:String>Flash</fx:String>
            <fx:String>Director</fx:String>
            <fx:String>Dreamweaver</fx:String>
            <fx:String>ColdFusion</fx:String>
        </mx:ArrayCollection>
    </s:List>

    <s:Button id="addFlex" label="Add Flex"
              click="addFlexToDP();"/>

</s:Application>