HTML file coding (filename form.html or whatever you choose):

<form action="process.php" method="post">
Enter a number between 1-100: <input type="text" name="msg" size="3">
<input type="submit" value="Guess">
</form>



PHP File coding (filename process.php):

<?php

// retrieve form data

$input = $_POST['msg'];

// use it

if ($input>30) {
echo "Your number is too big!";
}


if ($input<30) {
echo "Your number is too small!";
}


if ($input==30) {
echo "Your number is correct!";
}


?>