<form method="post" action="hash.php">
    Password: <input type="text" name="password" />
    <input type="submit" />
</form>

<br/>
<?php

    function generate_salt($length)
    {
        $characters = 'abcdefghijklmnopqrstuvwxyz123';
        $lastchar = strlen($characters) - 1;

        $salt = '';
        for ($i = 0; $i < $length; $i++)
        {
            $index = mt_rand(0, $lastchar);
            $character = $characters{$index};
            $salt .= $character;
        }

        return $salt;
    }

    if (!empty($_POST['password']))
    {

        $salt = generate_salt(32);
        echo '<br/>Salt: ' . $salt;
        $hash = hash('sha256', $salt . $_POST['password']);
        echo '<br/>Hash: ' . $hash;

        echo '<br/>Hash without salt: ' .
            hash('sha256', $_POST['password']);

    }

?>
