Controlling Weapons With MouseWheel

Hello, What I need to do is control a int with the MouseWheel. For instance I could clamp the int from 1 to 6 if I had 6 types of weapons.
there’s one problem though. I tried to look this up but all i could find was stuff for camera fov and zoom, and they always did:

function Update () {
camera.main.fov += Input.GetAxis("Mouse ScrollWheel");
}

And I tried doing that with the int and it doesn’t seem to be working… So does someone know if I forgot to do something. Thanks in advance.
Also by the way, im using javascript

EDIT:

Whenever i try:

public var ControlWeapon : int;

function Update () {
Debug.Log(ControlWeapon);
ControlWeapon += Input.GetAxis("Mouse ScrollWheel");
}

It will only debug ControlWeapon once. But when i open the Log the it shows a number to the far right going up very quickly.

Would something like this work?

    function Update () 
    {
        int a = 0; //you'd probably want to make this a global variable
     
        if (Input.GetAxis("Mouse ScrollWheel") > 0) // forward
        {
            a++;
        }
        if (Input.GetAxis("Mouse ScrollWheel") < 0) // back
        {
            a--;
        }
    }

Try ‘Camera’ with an upper case ‘C’. Also one degree of FOV is pretty small:

Camera.main.fov += Input.GetAxis("Mouse ScrollWheel") * 5.0;