weird behaviour with addChild - actionscript-3

Question

i am trying to add one Box to my application using the following code
<?xml version="1.0" encoding="utf-8"?>
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" layout="absolute" minWidth="955" minHeight="600"
>
<mx:HBox height="100%" width="100%" backgroundColor="red" borderColor="black"/>
<mx:Script>
<![CDATA[
import mx.collections.ArrayCollection;
import mx.containers.Box;
import mx.events.FlexEvent;
protected function button1_clickHandler():void
{
var box:Box = new Box();
box.setStyle("backgroundColor","blue");
box.height = 100;
box.width = 100;
//box.addChild(new Button());
addChild(box);
trace("children "+numChildren);
}
]]>
</mx:Script>
<mx:Button label="click" click="button1_clickHandler()" x="200" y="200" />
</mx:Application>
this code is work in flexBuilder.but it doesn't work while compiling in command prompt(using mxmlc command).
please suggest me on this issue, because my work is fully depending on command prompt.
thanks in advance
vengatesh s

Answer 1

This totally depends on the compiler you are using. If you are using the Flex 4+ compiler I would suggest you to try using addElement instead of addChild. The same code above just changes to
protected function button1_clickHandler():void
{
var box:Box = new Box();
box.setStyle("backgroundColor","blue");
box.height = 100;
box.width = 100;
/********** ----------- CHANGE----------------------********/
// This is the only change from your code
addElement(box);
/********** ----------- CHANGE----------------------********/
trace("children "+numChildren);
}