<html>
<head>
<script src="https://libs.baidu.com/jquery/1.10.2/jquery.min.js">
</script>
<script>
$(document).ready(function(){
$("#btn1").click(function(){
$("#p1").fadeToggle(2500)
});
$("#btn2").click(function(){
$("#p2").fadeToggle("slow","linear");
});
$("#btn3").click(function(){
$("#p3").fadeToggle("fast");
});
});
</script>
</head>
<body>
<button id="btn1">fadeToggle() milliseconds</button>
<button id="btn2">fadeToggle() slow</button>
<button id="btn3">fadeToggle() fast</button>
<p id="p1">This is a paragraph that takes 2500 milliseconds to fade out and in.</p>
<p id="p2">This is a slow, linear paragraph.</p>
<p id="p3">This is a fast paragraph.</p>
</body>
</html>