How do I switch the mouse buttons in flyspell mode in emacs?

I found it's rather odd that in flyspell mode in emacs, 
if a word is marked mis-spelled, I should press the middle 
mouse button to get the list suggested words, not the right 
mouse button, which does nothing. 

Since I am using a wheel mouse, my middle button is the 
wheel - not only it's hard to click on, it also sometimes 
mistaken as "paste" if I do click on it outside the popup 
suggestion menu. 

Is there a way I can weak the buttons so that I can use the 
right mouse button to bring up the menu of suggested words 
in flyspell mode? I think that should be default behavior 
as most "menu" type of lists are brought by right mouse 
button instead of the middle button.

Thanks for any tip about this. 

Tony