It is called onback because in Android we have an event that responds to the back button that executes this node, so that, the button that we put to exit and the button to go back from Android do the same.

To make the application cross-platform, we would have a button to exit or return to execute this same node, only in Android this node is executed automatically when we press the “backward” button of the system.

	<prop name="BTSALIR" type="B" img="logout.png" width="128p" height="128p" method="ExecuteNode(onback)" />

This is the code that executes both our button and the back of Android.

	<onback>
		<action name="runscript">
			<script language="VBScript">
	  			AppData.FailWithMessage -11888,"##EXIT##"
			</script>
		</action>
	</onback>

This business rule takes place when we press the BACK button of the ANDROID operating system. If we want to disable this button or perform any other custom action, we must use this node.

Example of code:

<onback>
	<action name="runscript">
		<script language="VBScript">
			'Cuando pulsemos el botón ATRAS de ANDROID, volveremos a la pestaña 1
			ui.ShowGroup "1","##BOUNCE##",2000,"##ZOOM_OUT##",800 
		</script>
	</action>
</onback>