Callback for dynamic populate control

When I call the populate method of dynamicpopulator control it calls the method as set in the ServiceMethod property.

How do i know when this method has completed execution so that I could perform some other task.

Is there a callback that I can access that tells me that the populate method has completed?

Please advise.

There might be a way to access the callback handler of the webservice proxy that gets invoked, but I'd say that an easier way would be to use the CustomScript property to call a function of your own design which returns to a handler you set up to do what you're looking for.