Mine

the index.php has:

<html>
<body>

<form action="sig.php" method="post">
Name: <input type="text" name="name" />
Age: <input type="text" name="age" />
<input type="submit" />
</form>

</body>
</html>

and the sig.php has:

<?php 

$handle = fopen('sig.txt', 'ra');
$name = $_POST["name"];
$age = $_POST["age"];
fwrite($handle, "$name age\n");
fclose ($handle);

?>