Zoomify layer over a Bing aerial map?

[jthomassie]

Is it possible to combine a Bing aerial map and add a layer on top with a Zoomify map which has 3 or 4 different image sources -- one for each zoom?

(For example, when you reach zoom level 8, the Zoomify tiles are from an image with county names, at zoom level 9 different tiles with city names would load, at zoom level 10 tiles may show schools, for example?

I know enough how to load the Bing aerial map, and I know how to create a Zoomify map, but I am not sure how to combine them and how to change the tile source based on zoom level.

Thanks, JT