<?xml version="1.0" encoding="utf-8"?>
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" layout="absolute">

	<mx:Style>
		.mine
		{
			font-weight: bold;
		}	
	</mx:Style>

	<mx:Script>
		<![CDATA[
			private function onClick():void
			{
				var arr:Array;
				var idx:int;
			
				arr = CN.getChildren();
				
				for(idx = 0; idx < arr.length; idx++)
				{
					if(arr[idx].id == "LB")
					{
						arr[idx].styleName = "mine";
						break;
					}	
				}
			}	
		]]>
	</mx:Script>

	<mx:Canvas id="CN">
		<mx:Label id="LB" x="167.5" y="36" text="Label"/>
		<mx:Button x="152.5" y="89" label="Button" click="onClick()"/>
	</mx:Canvas>
	
</mx:Application>