an example of skin
<?xml version="1.0" encoding="utf-8"?>
<Skin
xmlns:fx="
http://ns.adobe.com/mxml/2009"
xmlns:s="library://
ns.adobe.com/flex/spark"
xmlns:mx="library://
ns.adobe.com/flex/mx"
xmlns="rxg.*"
xmlns:rx="
http://rx.reflex.io/2010"
width="{labelDisplay+40}" height="{labelDisplay+14}"
>
<fx:Declarations>
<fx:Array>
<s:LinearGradient id="overFill" rotation="90">
<s:GradientEntry color="#222222" alpha="0.8"/>
<s:GradientEntry color="#FFFFFF" alpha="0.8"/>
</s:LinearGradient>
<s:LinearGradient id="downFill" rotation="90">
<s:GradientEntry color="#222222" alpha="0.8"/>
<s:GradientEntry color="#CCCCCC" alpha="0.8"/>
</s:LinearGradient>
<s:LinearGradient id="disabledFill" rotation="90">
<s:GradientEntry color="#333333" alpha="0.4"/>
<s:GradientEntry color="#666666" alpha="0.4"/>
</s:LinearGradient>
</fx:Array>
</fx:Declarations>
<states>
<s:State name="up" />
<s:State name="over" />
<s:State name="down" />
<s:State name="disabled" />
<s:State name="upAndSelected" stateGroups="selectedGroup"/>
<s:State name="overAndSelected" stateGroups="selectedGroup" />
<s:State name="downAndSelected" stateGroups="selectedGroup" />
<s:State name="disabledAndSelected" stateGroups="selectedGroup" />
</states>
<Rect id="rect" top="0" bottom="0" left="0" right="0" radiusX="10"
fill.over="{overFill}"
fill.down="{downFill}"
fill.disabled="{disabledFill}"
fill.selectedGroup="{overFill}"
>
<fill>
<s:LinearGradient id="upFill" rotation="90">
<s:GradientEntry color="#222222" alpha="0.6"/>
<s:GradientEntry color="#CCCCCC" alpha="0.6"/>
</s:LinearGradient>
</fill>
</Rect>
<Rect top="2" left="2" right="2" height="50%" topLeftRadius="19"
topRightRadius="19" bottomLeftRadius="4" bottomRightRadius="4">
<fill>
<s:LinearGradient id="shine" rotation="90">
<s:GradientEntry color="#FFFFFF" alpha=".5"/>
<s:GradientEntry color="#FFFFFF" alpha=".1"/>
</s:LinearGradient>
</fill>
</Rect>
<rx:Label
id="labelDisplay"
top="7" bottom="7" left="20" right="20"
text="{(target as Object).label}"
fontFamily="Verdana"
fontSize="12"
bold="true"
color="#ffffff"
/>
</Skin>