Welcome to Justanswer.com, my name is ***** ***** I will do my best to assist you.
First, I need to know the version of mac osx you have installed. Heres how to check.
Click the apple sign at the top left of your screen, then click about this mac. And then where it says version, send that to me as a reply.
Also, whats the full name brand and model of your mouse..
Thank you for your response.
Dustin S.Senior Technician and Network Switching Systems Operator / Maintainer.