Gun zooming in and out!

I am making a game and I need a gun to zoom in. I’ve made the animation and I want it to zoom in when I hold the right mouse button and zoom out when I let go! This is my code so far:

function Update () {

if(Input.GetMouseButton(1)){
    
    animation.Stop();
    animation.Play("m14_aim");
    
		}
		

else if(Input.GetMouseButtonUp(1)){

    animation.Stop("m14_aim");

}
	}

Thanks in advance!

Modify the camera field of view.

Thanks I got it in the end!