<canvas id="canvas"></canvas>
<script type="text/JavaScript">
var canvas = document.getElementById("canvas");
var ctx = canvas.getContext("2d");
ctx.setLineDash([7, 13]);
document.write(ctx.getLineDash());
ctx.beginPath();
ctx.moveTo(0, 100);
ctx.lineTo(500, 100);
ctx.stroke();
/*
run:
- - - - - - -
7,13
*/
</script>