a default update interface:
This interface is always used the first time a user installs
a version of an application on a machine. However, you can define
your own interface to use for subsequent instances. If your application
defines a custom update interface, specify a customUpdateUI element
in the application descriptor file for the currently installed application:
When the application is installed and the user opens an AIR file
with an application ID and a publisher ID that match the installed
application, the runtime opens the application, rather than the
default AIR application installer. For more information, see customUpdateUI.
The application can decide, when it is run (when the NativeApplication.nativeApplication object
dispatches an load event), whether to update the
application (using the Updater class). If it decides to update,
it can present its own installation interface (which differs from
its standard running interface) to the user.