Mouse scroll information

I am using this line

mpos = base.mouseWatcherNode.getMouse()

to access mouse position- the getX and getY give me this.

I also need to be able to detect if the scroll wheel is being used. It’s typically button 3 on most mice but I’m not talking about clicking the scroll wheel, I want to use it.

Any help would be great. Thanks.

it’s wheel_up, wheel_down events.