<form id="myForm" onsubmit="onSubmit(event)">
<input type="text" name="username" value="John Doe">
<input type="email" name="email" value="john@example.com">
<input type="submit">
</form>
<script>
function onSubmit(event) {
const form = document.getElementById('myForm');
const formData = new FormData(form);
const username = formData.get('username');
const email = formData.get('email');
alert(`username: ${username}; email: ${email}`);
}
</script>