drawImage(img,x,y) will draw an image. You need to replace the "x" and "y" with the position you want to draw the image. The first parameter is the image that it will draw. For no dont worry about it.
Follow the steps below
ctx.drawImage(img,50,50);
ctx.drawImage(img,150,50);
ctx.drawImage(img,150,50);
img.src = 'http://goo.gl/KXVpTD';