Flex Tree Control - how to set Tree control LABEL as CLICKABLE?

The following is sample code to make Tree Control Node label as clickable.

<mx:Script>

    <![CDATA[

        import mx.collections.ICollectionView;

        import mx.events.ListEvent;

        private function tree_itemClick(evt:ListEvent):void {

            var item:Object = Tree(evt.currentTarget).selectedItem;

            if (tree.dataDescriptor.isBranch(item)) {

                tree.expandItem(item, !tree.isItemOpen(item), true);

            }

        }

]]>

</mx:Script>

<mx:XML id="dp">

    <root>

        <folder label="Main Item">

            <folder label="Sub Item1">

                <item label="Sub Item11" />

                <item label="Sub Item21" />

                <item label="Sub Item31" />

                <item label="Sub Item41" />

                <item label="Sub Item51" />

            </folder>

            <item label="Sub Item2" />

            <item label="Sub Item3" />

        </folder>

    </root>

</mx:XML>

<mx:Tree id="tree" dataProvider="{dp}" showRoot="false"  labelField="@label" width="300" rowCount="6"

        itemClick="tree_itemClick(event);" />

In the above code, if we observe "itemClick" has been added to "tree" component. So, if we click on LABEL, itemClick event will be fired. This will call the "tree_itemClick" function, where it has the code to expand the node item.