How To Make Different Admin And Theme Languages

Hey folks!
WP-Snippet.com gave us a great solution, how to manage different language for dashboard and theme in WordPress.
But remember to delete language define in wp-config.php first!

<?php
// setup one language for admin and the other for theme
// must be called before load_theme_textdomain()

function set_my_locale($locale) {
$locale = ( is_admin() ) ? "en_US" : "it_IT";
setlocale(LC_ALL, $local );
return $locale;
}
add_filter( 'locale', 'set_my_locale' );
?>

Thanks again WP-Snippet.com !