I'm trying to figure out how to change the default functionality of the middle mouse button.

I would like to have:
1) Middle button click and drag the view (like the Pan tool)
2) Mouse wheel zoom in / out

I've been looking at deriving from NMouseWheelScrollAndZoomTool and making my own, and then attempting to replace the default tool with my new one, but I'm not convinced that's the right way to do it, or that I'm not doing a whole lot more work than I need to.

Any suggestions or assistance would be appreciated.

Herb.