JS Canvas Lasers Random Fill In Area SRC V2

<!DOCTYPE html>
<html>
<body bgcolor="#000000" onload="var i=setInterval('drawit()',100);">

<canvas id="myCanvas" width="1000" height="1000" style="border:10px;color:red;">
Your browser does not support the HTML5 canvas tag.</canvas>

<script>
var onetimecolor=prompt("Enter Your Favorite Color:(ie:Red)");
function drawit(){
var c = document.getElementById("myCanvas");
var ctx = c.getContext("2d");
ctx.strokeStyle=(onetimecolor);
ctx.lineThickness= "1000";
for(var i=0;i<20;i++){
ctx.beginPath(Math.random()*1000,Math.random()*1000);
var Line=(Math.random()*1000);
var Line1=(Math.random()*1000);
ctx.moveTo(Line1+Math.floor(Math.random()*500), Line);
ctx.lineTo(Line, Line1-Math.floor(Math.random()*500));
ctx.stroke();
}
}
</script>

</body>
</html>