nome del modello di input html5
echo '<input type="text" maxlength="32" name="first_name" pattern="[A-Za-z]{1,32}" value="'.$_SESSION['user_first_name'].'" required>';
html5 modello di input nome
echo '<input type="text" maxlength="32" name="first_name" pattern="[A-Za-z]{1,32}" value="'.$_SESSION['user_first_name'].'" required>';