Rotate View Around Z-Axis

It seems that I can only rotate the perspective view around the x and y axes. How can I rotate it around the z axis? I can’t seem to get my view positioned the way I want it because of this limitation.
thanks,
rex

Have a look at these controls in Options:

Thanks John,

Where can I read about what each of these choices means?

rex

The Rhino Help article describes them.
Click the Help button on the bottom corner of the dialog.