Must swap mouse buttons 2 and 3 on MacOS X

[David C.]

I'm using Emacs version 21.3.50 on MacOS X.  (emacs-version) returns:

        "GNU Emacs 21.3.50.1 (powerpc-apple-darwin6.3)
         of 2002-12-20 on phantom.local."

I am using a Microsoft Wheel Mouse.  When I click the center button (the 
wheel), Emacs gets <mouse-3>.  When I click the right button, Emacs gets 
<mouse-2>.

On other systems (X11 and Windows), it is the opposite - clicking the 
wheel generates <mouse-2> and clicking the right button generates <mouse-3>.

I think this is a bug in the MacOS X port.  If this is not considered a 
bug by the developers, could someone either provide an option for 
swapping mouse-2 and mouse-3 or explain why such an option should not be 
implemented.

Thanks in advance.

-- David