HTML DOM 允许 JavaScript 对 HTML 事件作出反应。

Mouse Over Me

Click Me

<!--

function clickMeEvent(obj) {

  if (obj.innerHTML == "Goodbye") {

    obj.style.display = "none";

  } else if (obj.innerHTML == "Thank You") {

    obj.innerHTML = "Goodbye";

  } else if (obj.innerHTML == "Click Me<br>Click Me Again<br>And Again") {

    obj.innerHTML = "Thank You";

  } else if (obj.innerHTML == "Click Me<br>Click Me Again") {

    obj.innerHTML = obj.innerHTML + "<br>And Again";

  } else {

    obj.innerHTML = obj.innerHTML + "<br>Click Me Again";

  }

}

//-->