how to horizontally align a Group located inside a VGroup?

[modjklist]

Hi Experts,

I have the following rectangle and lines oriented correctly with each other
inside a Spark Group.  

How would I then horizontally center this group in the VGroup (without changing 
the alignment of the rect and lines within the Group)? 

I tried using a horizontalCenter="0" in the Group declaration, but no effect.


<s:VGroup width="100%" height="100%" paddingBottom="20" paddingLeft="20" 
paddingRight="20" paddingTop="20" gap="0">

    <s:Group id="dgGroup" width="300">

        <s:Rect top="0" width="{this.dgGroup.width}" left="-1" height="50">
            <s:stroke>
                <s:SolidColorStroke color="0xff0000" weight="1"/>
            </s:stroke>
        </s:Rect>
                                                
        <s:Line id="l1" left="-1" top="-1" bottom="-1"> 
            <s:stroke>
                <s:SolidColorStroke color="0xffffff" weight="1" />
            </s:stroke>
        </s:Line>
                                        
        <s:Line id="l2" left="0" top="-1" bottom="0"> 
            <s:stroke>
                <s:SolidColorStroke color="0x00FF00" weight="1"/>
            </s:stroke>
        </s:Line>

    </s:Group>

</s:VGroup>