text: 
  
  var canvas = document.getElementById('canvas'),
      context = canvas.getContext('2d');
  
  context.lineWidth = 2;
  context.font = '24px Helvetica';
  context.lineJoin = 'round';
  
  context.fillText('Click anywhere to erase', 175, 40);
  context.strokeRect(75,100,200,200);
  context.fillRect(325,100,200,200);
  
  context.canvas.onmousedown = function(e) {
      context.clearRect(0,0,canvas.width,canvas.height);
  };
  
  
  