code: function initWebGL() {
    gl = null;
  
    try {
      gl = canvas.getContext("experimental-webgl");
    }
    catch(e) {
      alert(e);
    }
  
    // If we don't have a GL context, give up now
  
    if (!gl) {
      alert("Unable to initialize WebGL. Your browser may not support it.");
    }
  }
docs: initWebGL  Initialize WebGL, returning the GL context or null if WebGL isn't available or could not be initialized.