How can i dedect Mouse Up/Down scrolling in Opengl (C++) ?

I’m new on this forum so i’m sorry if i have bad thing like my english.

I wan’t dedect mouse scrolling for zoom in & zoom out.
I can zoom using keyboard input but i don’t know how can i use mouse scrolling for zoom.

Best Regards. -Asokanta

Which os and platform are you using?
If you are using windows, then the Mouse Wheel Event will do the job for you.