​x
 
<!DOCTYPE html>
<html>
<body>
​
<img id="myImg" src="/i/photo/beijing.jpg" width="750">
​
<p>单击按钮可将图像的宽度更改为 450px。</p>
​
<button onclick="myFunction()">试一试</button>
​
<script>
function myFunction() {
  document.getElementById("myImg").width = "450";
}
</script>
​
</body>
</html>
​