​x
 
<!DOCTYPE html>
<html>
<head>
<style> 
#myDIV {
  width: 100px;
  height: 100px;
  background-color: coral;
  color: white;
}
</style>
</head>
<body>
​
<p>点击“试一试”按钮改变 DIV 元素的高度：</p>
​
<button onclick="myFunction()">试一试</button>
​
<div id="myDIV">
  <h1>myDIV</h1>
</div>
​
<script>
function myFunction() {
  document.getElementById("myDIV").style.height = "500px";
}
</script>
​
</body>
</html>
​