gistfile1.txt

function greenLines(){
	var imgdata = ctx.getImageData(0,0,600,600);
	for (var i =0; i < imgdata.data.length; i+=40){ //move forward 40 spots because each 
	                                                //pixel is 4 array spots and we wanna move 10 pixels
		imgdata.data[i] = 0;
		imgdata.data[i+1]=255;
		imgdata.data[i+2]=0;
		imgdata.data[i+3] = 255;
	}
	
	ctx.putImageData(imgdata, 0, 0);
}