actionscript 3 - Setting property of Object in Flex -

<mx:canvas id="maincanvas" backgroundcolor="7000" width="100%" height="100%">     <mx:textarea backgroundalpha="0"/> </mx:canvas> 

however if try creating new textarea object via:

var textarea:textarea = new textarea (); textarea.backgroundalpha = 0; maincanvas.addchild(textarea); 

flex throws error :

1119: access of possibly undefined property backgroundalpha through reference static type mx.controls:textarea.

backgroundalpha style, you've got set with:

textarea.setstyle("backgroundalpha", 0);