[flexcoders] Setting properties of UIComponents with actionscript

[Josh Millstein]

Hello,

How can I set paddingTop etc. when creating an HBox in actionscript.  I
can't do 

hBox:HBox = new HBox();
hBox.paddingTop = 10;

Also, how can I set a HBox width to a percentage.
I can't do 
hBox.width = "100%";

Thanks for any help