<html>
<head>
<script src="https://libs.baidu.com/jquery/1.10.2/jquery.min.js">
</script>
<script>
$(document).ready(function(){
$("button").click(function(){
$("input").change();
});
});
</script>
</head>
<body>
<p>Click the button to trigger the change event (even if the element has not been changed).</p>
<button>Trigger change event for input field</button>
<p>Enter your name: <input value="Donald" onchange="alert(this.value)" type="text"></p>
</body>
</html>