<?xml version="1.0" encoding="utf-8"?>
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml">

    <mx:Style>
        .myCustomLinkButtonStyleName {
            fontWeight: normal;
        }
    </mx:Style>

    <mx:Array id="arr">
        <mx:Object label="One" />
        <mx:Object label="Two" />
        <mx:Object label="Three" />
        <mx:Object label="Four" />
    </mx:Array>

	<mx:Form>
		<mx:FormItem label="default:">
		    <mx:LinkBar id="linkBar1"
		            dataProvider="{arr}"
		            fontWeight="normal"  />
		</mx:FormItem>
		<mx:FormItem label="linkButtonStyleName:">
		    <mx:LinkBar id="linkBar2"
		            dataProvider="{arr}"
		            linkButtonStyleName="myCustomLinkButtonStyleName" />
		</mx:FormItem>
	</mx:Form>

</mx:Application>