MD5 ENCRYPTER

<head>
<title>MD5 Encryter</title>
</head>

<form action="" method="post">
To convert: <input type="text" name="string" />
<input type="submit" name="submit" value="MD5">

<?php
    if(!isset($_POST['submit'])) {
        die("<br>Please, enter a string");
    }
    else {
        $string = $_POST['string'];
        $MD5 = md5($string);

        if($string == NULL) {
            die("<br>Please, enter a string.");
        }
        die("<br><p>Your MD5 hash is: "."$MD5");
    }
?>