<?xml version="1.0" encoding="utf-8"?>
<!-- http://blog.flexexamples.com/2007/12/13/creating-nonmodal-alert-dialog-boxes-in-flex/ -->
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml"
        layout="vertical"
        verticalAlign="middle"
        backgroundColor="white" viewSourceURL="srcview/index.html">

    <mx:Style>
        Alert {
            modalTransparencyColor: black;
        }
    </mx:Style>

    <mx:Script>
        <![CDATA[
            import mx.controls.Alert;

            private function button_click(evt:MouseEvent):void {
                var flags:uint = Alert.OK | Alert.YES;
                if (checkBox.selected) {
                    flags |= Alert.NONMODAL;
                }
                var alert:Alert = Alert.show("Message", "", flags);
                alert.title = alert.toString();
            }
        ]]>
    </mx:Script>

    <mx:ApplicationControlBar dock="true">
        <mx:CheckBox id="checkBox"
                label="Alert.NONMODAL:"
                labelPlacement="left"
                selected="true" />

        <mx:Spacer width="100" />

        <mx:Button label="Launch Alert"
                click="button_click(event);" />
    </mx:ApplicationControlBar>

</mx:Application>