<?xml version="1.0" encoding="utf-8"?>
<!-- http://blog.flexexamples.com/2008/09/26/dynamically-styling-error-tips-in-flex/ -->
<mx:Application name="errorTip_borderColor_test_2"
        xmlns:mx="http://www.adobe.com/2006/mxml"
        layout="vertical"
        verticalAlign="middle"
        backgroundColor="white" viewSourceURL="srcview/index.html">

    <mx:Script>
        <![CDATA[
            import mx.events.FlexEvent;

            private function comboBox_valueCommit(evt:FlexEvent):void {
                if (comboBox.selectedIndex > -1) {
                    var value:String = comboBox.selectedItem.data;
                    var cssObj:CSSStyleDeclaration;
                    cssObj = StyleManager.getStyleDeclaration(".errorTip");
                    cssObj.setStyle("borderColor", value);
                    textInput.setStyle("errorColor", value);
                    textInput.errorString = errStr;
                } else {
                    textInput.errorString = "";
                }
            }

            private function button_click(evt:MouseEvent):void {
                comboBox.selectedIndex = -1;
            }
        ]]>
    </mx:Script>

    <mx:Array id="arr">
        <mx:Object label="Red"    data="red" />
        <mx:Object label="Orange" data="haloOrange" />
        <mx:Object label="Yellow" data="yellow" />
        <mx:Object label="Green"  data="haloGreen" />
        <mx:Object label="Blue"   data="haloBlue" />
    </mx:Array>

    <mx:String id="errStr">Oh noes, an errata!</mx:String>

    <mx:ApplicationControlBar dock="true">
        <mx:Form styleName="plain">
            <mx:FormItem label="errorColor:">
                <mx:ComboBox id="comboBox"
                        dataProvider="{arr}"
                        prompt="Please select a color:"
                        valueCommit="comboBox_valueCommit(event);" />
            </mx:FormItem>
        </mx:Form>
        <mx:Spacer width="100%" />
        <mx:Button label="Deselect ComboBox"
                click="button_click(event);" />
    </mx:ApplicationControlBar>

    <mx:TextInput id="textInput" />

</mx:Application>