<!DOCTYPE html> <html> <head> <meta charset="UTF-8"> <script type="text/javascript"> function bodyonload() { var canvas=document.getElementById('test'); var ctx = canvas.getContext("2d"); ctx.fillStyle = 'green'; ctx.fillRect(-1, 50, 151, 50); // left at -1 ctx.fillStyle = 'red'; ctx.rect(-1, 100, 151, 50); // left at -1 ctx.fill(); ctx.fillStyle = 'blue'; ctx.fillRect(0, 150, 150, 50); // left at 0 } </script> </head> <body onload="bodyonload();"> <canvas id="test" width="200" height="200"></canvas> </body> </html>