You didn't share what language you were using. Such has different answers for Visual Basic, C++, Real Basic, Forth and Java.
-> Also, the Visual Basic answer is one I won't duplicate here since it's on google.com
Bob
I need help on creating an event for the "on mouse wheel" property in a form - when I open the form I want to be able to use the mouse wheel to scroll up and down, right now it doesn't.
Any help is appreciated!

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic