<html>
<body>
<p>当提交表单是，触发函数并弹出提示信息。</p>
<form action="demo-form.php" onsubmit="myFunction()">
输入名字: <input type="text" name="fname">
<input type="submit" value="提交">
</form>
<script>
function myFunction() {
alert("表单已提交");
}
</script>
</body>
</html>