[OpenLayers-Users] Change layer on max zoom level

[emmexx]

I'm asked to implement a behaviour similar to the one used in gpsies.
If the map baselayer is, for example, Google Terrain (max zoom level:
16) when the user tries to zoom the baselayer switches to Google Streets
(max zoom level: 22).

I checked the zoomend event of the map object but it is not triggered
when trying to zoom beyond max level.

Any suggestion?

Thank you
	maxx