Unable to use track box to increase, decrease page size

[jhoomjhoom]

Hello,

I just realized that I am no longer able to use the track box (is that what they call it) on my Mac Air to increase or decrease the page size. Instead I must use command + or command -.

Please tell me how to fix this.

 

[jhoomjhoom]

It is a track pad, that is the terminology. It seems I am able to use the track pad for other things, but not increasing or decreasing the page size like I did before.