zooming in and out with mouse wheel

im making an rpg, and im now onto the stage of doing the camera. orbiting my character ect. but i dont know how to make my camera zoom in and out using the mouse wheel, can anyone help me?

Generally 'zooming' in game is just moving the camera closer or farther away from the target. To make it zoom just adjust the camera distance with the scroll wheel.

float cameraDistanceMax = 20f;
float cameraDistanceMin = 5f;
float cameraDistance = 10f;
float scrollSpeed = 0.5f;

void Update()
{
    cameraDistance += Input.GetAxis("Mouse ScrollWheel") * scrollSpeed;
    cameraDistance = Mathf.Clamp(cameraDistance, cameraDistanceMin, cameraDistanceMax);

    // set camera position
}

Maybe should to manipulate with FOV when non-orthographic camera mode?