First, you have to have create database table for default language and allowed languages.
CREATE TABLE IF NOT EXISTS `tbl_languages` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`name` varchar(20) CHARACTER SET utf8 COLLATE utf8_unicode_ci NOT NULL,
`lang` varchar(2) CHARACTER SET utf8 COLLATE utf8_unicode_ci NOT NULL,
`flagpath` varchar(40) CHARACTER SET utf8 COLLATE utf8_unicode_...