draw image from a sprite

HTML5_drawImage.js

//get canvas element
var canvas = document.getElementById("main");

//get context
var ctx = canvas.getContext('2d');

//create new image object
var image = new Image();

//set callback for when the image actually loads
image.onload = function () {
  //actual draw image
  ctx.drawImage(image, pStill.x, pStill.y, pStill.w, pStill.h, 0, 0, pStill.w, pStill.h);
};

//load the image
image.src = "mario.png";