 the divcontainer
  divContainerElement.appendChild(div);

  // Use our boilerplate utils to compile the shaders and link into a program
  var program = webglUtils.createProgramFromSources(gl,
      [vertexShaderSource, fragmentShaderSource]);

  // look up where the vertex data needs to go.
  var positionAttributeLocation = gl.getAttribLocation(program, "a_position");
  var colorAttributeLocation = gl.getAttribLocation(program, "a_color");

  // look up uniform locations
  var matrixLocation = gl.getUnifor