Generate event when leaving a mashup

does anyone know of a way to generate an event when leaving a mashup?

I have a UI mashup which allows a user to configure some settings. I wish to write those settings to a file without the user having to press a 'save' button. I was hoping that I could use the menu widget that drives the mashups but there doesn't seem to be any events emitted. I have a service that dynamically returns the data (menu items) for the menu and tried to use the 'selected row changed' event, but it doesn't seem like this is emitted when used with a menu widget.

Thanks in advance

K