Draw grid of blocks on canvas

gistfile1.txt

var c = document.createElement('canvas');
c.height = window.innerHeight;
c.width = window.innerWidth;
var ctx = c.getContext('2d');

function blocks(size) {
	//draw row
	for(var j=0, x=c.height/size; j<x; j++) {
		//draw block
		for(var i = 0, l = c.width/size; i<l; i++) {
			var red = Math.floor(Math.random() * 256);
			var green = Math.floor(Math.random() * 256);
			var blue = Math.floor(Math.random() * 256);
			var alpha = 255;

			ctx.beginPath();
			ctx.fillStyle = "rgba( "+red+", "+green+", "+blue+", "+alpha+")";

			ctx.rect(i*size,j*size,size,size);
			
			ctx.fill();
		}	
	}
}

blocks(10)