utton {
        margin: 0;
      }
      button + button {
        float: right;
      }
      textarea {
        display: block;
        width: 494px;
        height: 100px;
        margin-bottom: 1em;
      }
      iframe { display: none; }
    </style>
  </head>
  <body>
    <h1>Evalbox</h1>
    <p class='lead'>A toy demonstration of sandboxing. Type some JavaScript into
    the field below; clicking one of the two buttons will run the code through
    <code>eval()</code> in an <code>iframe</code>. The d