[flexcoders] Autocenter a form

[markgoldin_2000]

Is there a way to center a form horizontally? Here is my code:

 <mx:Canvas label="Cause" width="100%" height="100%" id="cause">
        <mx:HBox horizontalAlign="center">
                <accidents:causes id="Cause"/> 
        </mx:HBox>      
 </mx:Canvas>

where causes is an mxml component based on a form. When I run this code 
the form is positioned on the left side of the box.

Thanks