alias zoom [
    if (= $arg1 1) [
        if (=f $sensitivity (scopesens)) [] [
            alias oldsens $sensitivity
            // avoid error if using 0.001 as sensitivity
            newsens = (scopesens)
            if (> (*f 1 1000) $newsens) [
                if (< 1000 $newsens) [
                sensitivity (scopesens)
                ] []
            ] []
            setscope  1
        ]
    ] [
        sensitivity $oldsens
        setscope 0
    ]
]