Untitled

<?php
session_start();

$db =  mysqli_connect("localhost","root","" ,"authentication");

$salt = '$5$rounds=5000$usesomesillystringforsalt$';

function MakeSafe($variable, $db)
{
    return mysqli_real_escape_string($db, $_POST[$variable]);
}

if( isset($_POST['register_btn']))
 {

 $username = MakeSafe('username', $db );
 $email = MakeSafe('email', $db );
 $password = MakeSafe('password',$db );
 $password2 = MakeSafe('password2', $db );

     if ($password == $password2)
     {
         $password = crypt($password, $salt);

         $sql = sprintf("INSERT INTO users (username, email ,password) VALUES ('%s', '%s', '%s')",
                            $username,
                            $email,
                            $password);

        if(mysqli_query($db, $sql))
        {
          $_SESSION['message'] = "You are now logged in" ;
          $_SESSION['username'] = $username;
          header("location: glowna.html");
        }
     }else
     {
         $_SESSION['message'] = "The two password do not match" ;


     }
 }

?>


<!DOCTYPE html>
<html lang='pl'>
 <meta charset="utf-8">
 <meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">
    <meta name="description" content="">
    <meta name="author" content="">
<head>
<title>rejestracja</title>
<style>
body
{
    background: url(img/tlo.jpg);
}
</style>
</head>
<body>
<div class="header">
                  <h1>Rejestracja</h1>
</div>
        <form method="post" action="crypt.php">
<table>
      <tr>
      <td>Nazwa użytkownika:</td>
              <td><input type="text" name="username" class="textInput" required></td>
      </tr>
      <tr>
      <td>E-mail:</td>
               <td><input type="email" name="email" class="textInput" required></td>
      </tr>
      <tr>
      <td>Hasło:</td>
                <td><input type="password" name="password" class="textInput" required></td>
      </tr>

      <tr>
               <td>Potwierdź hasło:</td>
      <td><input type="password" name="password2" class="textInput" required></td>
      </tr>

      <tr>
      <td></td>
               <td><input type="submit" name="register_btn" value="Rejestruj"></td>
      </tr>

</table>
</form>
</body>
</html>