Triggering data transfer when leaving a page

Hi,

I want to control a bsp-application (running in a browser in the GUI) from the program which started the application.

1) The control information can be transferred to the bsp via parameters in an url to the same bsp (or is there a better way?)

2) When an new 'control-url' is sent to the bsp the data in the view is not transferred to the corresponding fields in the model. How can I force the data transfer? Do I need an 'onUnLoad'-event which triggers the 'normal' methods of the controller? And if so, in which bsp-extension tag can I register this handler?

Regards, Martin