  <h2>Handler</h2>
  <button onclick="this.style.color='red'">点击我试试</button>
  <div id="output"></div>

  <h2>Handler2</h2>
  <button onclick="this.style.color='red';document.getElementById('output2').innerText='按钮已被点击'">点击我试试</button>
  <div id="output2"></div>