Creating a simple image map in Flex 4

<?xml version="1.0" encoding="utf-8"?>
<!-- http://blog.flexexamples.com/2010/03/22/creating-a-simple-image-map-in-flex-4/ -->
<s:Application name="Spark_Graphic_mouseEnabledWhereTransparent_test"
        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:controlBarContent>
        <s:Label text="alpha:" />
        <s:HSlider id="sldr"
                minimum="0.0" maximum="1.0"
                value="0.3"
                snapInterval="0.1" stepSize="0.1" />
    </s:controlBarContent>
 
    <fx:Script>
        <![CDATA[
            import mx.controls.Alert;
        ]]>
    </fx:Script>
 
    <s:Group horizontalCenter="0" verticalCenter="0">
        <s:BitmapImage id="img" source="@Embed('fx_appicon-tn.gif')" />
        <s:Graphic buttonMode="true"
                mouseEnabledWhereTransparent="false"
                toolTip="Link 1"
                useHandCursor="true"
                click="Alert.show('click1');">
            <s:Rect id="hit1"
                    width="20" height="20"
                    x="5" y="5">
                <s:fill>
                    <s:SolidColor color="red" alpha="{sldr.value}" />
                </s:fill>
            </s:Rect>
        </s:Graphic>
        <s:Graphic buttonMode="true"
                mouseEnabledWhereTransparent="false"
                toolTip="Link 2"
                useHandCursor="true"
                click="Alert.show('click2');">
            <s:Ellipse id="hit2"
                    width="20" height="20"
                    x="25" y="10">
                <s:fill>
                    <s:SolidColor color="haloOrange" alpha="{sldr.value}" />
                </s:fill>
            </s:Ellipse>
        </s:Graphic>
        <s:Graphic buttonMode="true"
                mouseEnabledWhereTransparent="false"
                toolTip="Link 3"
                useHandCursor="true"
                click="Alert.show('click3');">
            <s:Path id="hit3"
                    data="M 10 0 L 20 20 L 0 20 L 10 0 Z"
                    x="10" y="25">
                <s:fill>
                    <s:SolidColor color="yellow" alpha="{sldr.value}" />
                </s:fill>
            </s:Path>
        </s:Graphic>
    </s:Group>
 
</s:Application>