[Flex] Validation error message 에 Style 적용하기

출처 : http://livedocs.adobe.com/flex/3/html/help.html?content=validators_5.html

Ex)

<?xml version="1.0"?>
<!-- validators\PNValidatorErrMessageStyle.mxml -->
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml">

    <!-- Use blue for the error message. -->
    <mx:Style>
        .errorTip { borderColor: #0000FF}
    </mx:Style>

    <!-- Define the PhoneNumberValidator. -->
    <mx:PhoneNumberValidator id="pnV"
        source="{phoneInput}" property="text"
        wrongLengthError="Please enter a 10-digit number."/>

    <!-- Define the TextInput control for entering the phone number. -->
    <mx:TextInput id="phoneInput"/>
    <mx:TextInput id="zipCodeInput"/>
</mx:Application>