<mx:button label=''button" click="reload(event)"/>
<mx:scirpt>
</mx:script>
<![CDATA[
                  function reload(event:MouseEvent):void{
                      var ref:URLRequest = new URLRequest("javascript:location.relaod(true)");
                      navigateToURL(ref,"_self");
                  }
]]>
</mx:script>