JS LFO/HFO Movie FX Flying Sauser SRC

<script>
var context = new AudioContext();
var lfo = context.createOscillator();
lfo.frequency.value = 12.0;
var hfo = context.createOscillator();
hfo.frequency.value = prompt('enter');
var modulationGain = context.createGain();
modulationGain.gain.value = 50;
lfo.connect(modulationGain);
modulationGain.connect(hfo.detune);
hfo.connect(context.destination);
hfo.start(0);
lfo.start(0);
</script>