JS Web Audio Oscillator Cross Fader FX SRC

<script>
var audioCtx=new AudioContext();
var oscillator = audioCtx.createOscillator();
var gainNode = audioCtx.createGain();
oscillator.connect(gainNode);
gainNode.connect(audioCtx.destination);
var WIDTH = window.innerWidth;
var HEIGHT = window.innerHeight;
var FreqMax = prompt("Enter Max Freq");
var VolMax = prompt("Enter Max Vol:");
var Freq = prompt("Enter Starting Freq:");
var Vol = prompt("Enter Starting Vol:");
oscillator.type = 'sawtooth';
oscillator.frequency.value = Freq;
oscillator.start();
gainNode.gain.value =Vol;
var CurX;
var CurY;
var CurZ;
var CurZZ;
document.onmousemove = updatePage;
function updatePage(e) {
CurZ = (window.Event) ? e.pageY : event.clientY + (document.documentElement.scrollLeft ? document.documentElement.scrollLeft : document.body.scrollLeft);
CurZZ = (window.Event) ? e.pageX : event.clientX + (document.documentElement.scrollTop ? document.documentElement.scrollTop : document.body.scrollTop);
CurX = (window.Event) ? e.pageX : event.clientX + (document.documentElement.scrollLeft ? document.documentElement.scrollLeft : document.body.scrollLeft);
CurY = (window.Event) ? e.pageY : event.clientY + (document.documentElement.scrollTop ? document.documentElement.scrollTop : document.body.scrollTop);
oscillator.frequency.value = (CurX/WIDTH) * FreqMax;
gainNode.gain.value = (CurY/HEIGHT) * VolMax;
oscillator.frequency.value = (CurZ-WIDTH) % FreqMax;
gainNode.gain.value = (CurZZ-HEIGHT) % VolMax;
oscillator.detune=(0);
}
function drawe(){
var canvas = document.getElementById("myCanvas");
var ctx = canvas.getContext("2d");
ctx.moveTo(event.x+CurX,event.y+CurZZ);
ctx.lineTo(event.x+CurX,event.y+CurZ);
ctx.stroke();
}
</script>
<html>
<body onmousemove="drawe();" onchange="drawe();" background-color="white">
<canvas id="myCanvas" width="1000" height="1000" style="background:darkorange;">
</canvas>
</body>
</html>