<!DOCTYPE html>
<html>
<body>
<h1>A Hidden Field (look in source code)</h1>
<form action="/action_page.php">
<label for="fname">First name:</label>
<input type="text" id="fname" name="fname"><br><br>
<input type="hidden" id="custId" name="custId" value="3487">
<input type="submit" value="Submit">
</form>
<p><strong>Note:</strong> The hidden field is not shown to the user, but the data is sent when the form is submitted.</p>
</body>
</html>