<?xml version="1.0" encoding="utf-8"?>
<!-- http://blog.flexexamples.com/2008/01/14/setting-a-labels-font-weight-on-a-flex-linkbar-and-togglebuttonbar-control/ -->
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml"
        layout="vertical"
        verticalAlign="middle"
        backgroundColor="white" viewSourceURL="srcview/index.html">

    <mx:Style>
        .myCustomLinkButtonStyleName {
            fontWeight: normal;
        }

        .myCustomButtonStyleName {
            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:LinkBar id="linkBar"
            dataProvider="{arr}"
            linkButtonStyleName="myCustomLinkButtonStyleName" />

    <mx:ToggleButtonBar id="toggleButtonBar"
            dataProvider="{arr}"
            buttonStyleName="myCustomButtonStyleName" />

</mx:Application>