在LinkButton中 textDecoration属性设置label的是否有下划线装饰，属性值分为"none","underline"
代码如下------>
<mx:LinkButton id="test" x="326" y="163" width="136" height="86" label="测试数据"
click="test1_clickHandler(event)" fontSize="22"
mouseOut="test.setStyle('textDecoration', 'none')"
mouseOver="test.setStyle('textDecoration', 'underline')" textDecoration="none"/>