title: HTML5 Canvas Context
body: <p>I have started reading/experimenting with HTML5.  All the tutorials I've seen for the HTML5 Canvas follow the pattern of JavaScript getting the canvas by ID, getting a 2d context, and then working with the context:</p>
  
  <pre><code> &lt;canvas id="myCanvas" width="300" height="200" style="border:1px solid"&gt;&lt;/canvas&gt;
   &lt;script&gt;
     var c=document.getElementById("myCanvas");
     var ctx=c.getContext("2d");
     ctx.fillStyle="cyan";
     ctx.fillRect(50,50,100,75);
   &lt;/script&gt;
  </code></pre>
  
  <p>I was wondering if there is any enumeration or constants for getting a Context for the Canvas.  </p>
  
  <p>Something like <code>Context.2D</code>, <code>Context.3D</code>, etc. (I know this isn't a real constant, just wondering if there is something like it somewhere in JavaScript or HTML5).  </p>
  
  <p>Every example I've seen, the call that is made is simply <code>getContext("2d")</code>.  This seems brittle, and also doesn't tell me what other (if any) contexts might be available. </p>