<html>
<head>
<script src="https://libs.baidu.com/jquery/1.10.2/jquery.min.js">
</script>
<script>
$(document).ready(function(){
$("input").keydown(function(){
$("input").css("background-color","yellow");
});
$("input").keyup(function(){
$("input").css("background-color","pink");
});
});
</script>
</head>
<body>
Enter your name: <input type="text">
<p>Enter your name in the input field above. It will change background color on keydown and keyup.</p>
</body>
</html>