Проверка уникальности созданного поля - CommunityBuilder

function checkUsernameAvailability( $username ) {
	global $_CB_database, $ueConfig;

	if ( ( ! isset( $ueConfig['reg_username_checker'] ) ) || ( ! $ueConfig['reg_username_checker'] ) ) {
		echo _UE_NOT_AUTHORIZED;
		exit();
	}
	// simple spoof check security
	cbSpoofCheck();
	cbRegAntiSpamCheck();
	
	$usernameISO =	utf8ToISO( $username );			// AJAX sends in utf8, we need to convert back to the site's encoding.

	if ( $_CB_database->isDbCollationCaseInsensitive() ) {
		$query	=	"SELECT COUNT(*) AS result FROM #__users WHERE username = '" . $_CB_database->getEscaped( ( trim( $usernameISO ) ) ). "'";
	} else {
		$query	=	"SELECT COUNT(*) AS result FROM #__users WHERE LOWER(username) = '" . $_CB_database->getEscaped( ( strtolower( trim( $usernameISO ) ) ) ). "'";
	}
	$_CB_database->setQuery($query);
	$dataObj	=	null;
	if ( $_CB_database->loadObject( $dataObj ) ) {
		if ( $dataObj->result ) {
			// funily, the output needs to be UTF8 again:
			echo '<span style="color:red;">' . sprintf( _UE_USERNAME_ALREADY_EXISTS, htmlspecialchars( $username ) ). "</span>";
		} else {
			echo '<span style="color:green;">' . sprintf( _UE_USERNAME_DOESNT_EXISTS, htmlspecialchars( $username ) ). "</span>";
		}
	} else {
		echo '<span style="color:red;">Search error!' . "</span>";
	}
}