Signal as MXML tag in Flex 4

SignalAsMXMLTag.mxml

<?xml version="1.0"?>
<!--
  ~ RegFormRLSExample - RegView.mxml
  ~
  ~ Copyright (c) 2010. Newtriks Ltd <simon@newtriks.com>
  ~ Your reuse is governed by the Creative Commons Attribution 3.0 License
  -->
<s:Group xmlns:fx="http://ns.adobe.com/mxml/2009"
		 xmlns:s="library://ns.adobe.com/flex/spark"
		 xmlns:mx="library://ns.adobe.com/flex/halo"
		 xmlns:signals="org.osflash.signals.*">

	<fx:Declarations>
		<signals:Signal id="submitClicked"/>
	</fx:Declarations>

	<s:layout>
		<s:VerticalLayout />
	</s:layout>

	<mx:Form>
		<mx:FormItem label="Email:">
			<s:TextInput id="email_ti"/>
		</mx:FormItem>
		<mx:FormItem label="Password:">
			<s:TextInput id="password_ti" displayAsPassword="true"/>
		</mx:FormItem>
	</mx:Form>

	<s:Button label="Submit" click="submitClicked.dispatch()"/>

</s:Group>