​x
 
<html>
<head>
<script type="text/javascript" src="/jquery/jquery.js"></script>
<script type="text/javascript">
$(document).ready(function(){
  $("p").mouseenter(function(){
    $("p").css("background-color","yellow");
  });
  $("p").mouseleave(function(){
    $("p").css("background-color","#E9E9E4");
  });
  $("#btn1").click(function(){
    $("p").mouseenter();
  });  
  $("#btn2").click(function(){
    $("p").mouseleave();
  }); 
});
</script>
</head>
<body>
<p style="background-color:#E9E9E4">请把鼠标指针移动到段落上。</p>
<button id="btn1">触发段落的 mouseenter 事件</button><br />
<button id="btn2">触发段落的 mouseleave 事件</button>
</body>
</html>
​