<!DOCTYPE html>
<html>
<body>
<h3>访问 LI 元素</h3>
<ol>
<li id="myLi">Coffee</li>
<li>Tea</li>
<li>Milk</li>
<li>Water</li>
</ol>
<p>点击按钮设置列表项从数字 "300" 开始递增，而不是从 "1" 开始递增。</p>
<button onclick="myFunction()">尝试一下</button>
<script>
function myFunction()
{
var x = document.getElementById("myLi");
x.value = "300";
}
</script>
</body>
</html>
