function simulation() {
    var v = -1000;
    var s = 50000;
    var fuel = 10000;
    var schub = false;
    update();

    function switchOn() {
        update();
        schub = true;
    }

    function switchOff() {
        update();
        schub = false;
    }

    function a() {
        if (schub == false || fuel <= 0)
            return -1.63;
        else {
            fuel = fuel - 100;
            return -1.63 + 12;
        }
    }

    function update() {
        if (checkGameOver() == true) {
            setStartValues();
            showCurrentValues()
        }
        else if ((checkGameOver() == false) && (s < 0) && (v > -10)) {
            setStartValues();
            showCurrentValues();
        }
        else {
            v = v + a();
            s = s + v;
            showCurrentValues();
        }
    }

    function checkGameOver() {
        if (s < 0)
            if (v < -10) {
                alert("Zerschellt. Game Over");
                return true;
            }
            else {
                return false;
            }
        else {
            return false;
        }
    }

    function setStartValues() {
        v = -1000;
        s = 50000;
        fuel = 10000;
        schub = false;
        return;
    }

    function showCurrentValues() {
        $("#height").html("Höhe: " + s + " m");
        $("#speed").html("Geschwindigkeit: " + v + " m/s");
        $("#fuel").html("Treibstoffvorrat: " + fuel + " l");
        return;
    }

    $("body").append("<div id='height'>Höhe: </div>");
    $("body").append("<div id='speed'>Geschwindigkeit: </div>");
    $("body").append("<div id='fuel'>Treibstoffvorrat: </div>");

    $("body").append("<button id='energy'>Triebwerk an</button>");
    $("body").append("<button id='no-energy'>Triebwerk aus</button>");

    $("#energy").click(switchOn);
    $("#no-energy").click(switchOff);
}

$(document).ready(simulation);