​x
 
<!DOCTYPE html>
<html>
<body>
​
<p>本例演示如何将 "onmouseenter" 和 "onmouseleave" 事件分配给 h1 元素。</p>
​
<h1 id="demo" onmouseenter="mouseEnter()" onmouseleave="mouseLeave()">请把鼠标悬停在我上面</h1>
​
<script>
function mouseEnter() {
  document.getElementById("demo").style.color = "red";
}
​
function mouseLeave() {
  document.getElementById("demo").style.color = "black";
}
</script>
​
</body>
</html>
​