PHP Point of Sale modification (add multi store/locations)

Looking for someone to do modification of php point of sale ([login to view URL]) The modification needed is central management of multiple stores/locations in the same database. Will need one extra column in the tables to record the store/location id. employees, customers, stock, orders to be assigned to store/location by adding additional column with the store/location id. example: CREATE TABLE IF NOT EXISTS `phppos_customers` ( `person_id` int(10) NOT NULL, `account_number` varchar(255) COLLATE utf8_unicode_ci DEFAULT NULL, `company_name` varchar(255) COLLATE utf8_unicode_ci NOT NULL, `taxable` int(1) NOT NULL DEFAULT '1', `deleted` int(1) NOT NULL DEFAULT '0', UNIQUE KEY `account_number` (`account_number`), KEY `person_id` (`person_id`), KEY `deleted` (`deleted`) ) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci; This is the original customers table, we'll need new column 'location_id' (ABC01 for example) employees table structure is similar, so it will be the same. orders/sales table CREATE TABLE IF NOT EXISTS `phppos_sales` ( `sale_time` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP, `customer_id` int(10) DEFAULT NULL, `employee_id` int(10) NOT NULL DEFAULT '0', `comment` text COLLATE utf8_unicode_ci NOT NULL, `show_comment_on_receipt` int(1) NOT NULL DEFAULT '0', `sale_id` int(10) NOT NULL AUTO_INCREMENT, `payment_type` varchar(255) COLLATE utf8_unicode_ci DEFAULT NULL, `cc_ref_no` varchar(255) COLLATE utf8_unicode_ci NOT NULL, `deleted` int(1) NOT NULL DEFAULT '0', `suspended` int(1) NOT NULL DEFAULT '0', PRIMARY KEY (`sale_id`), KEY `customer_id` (`customer_id`), KEY `employee_id` (`employee_id`), KEY `deleted` (`deleted`) ) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci AUTO_INCREMENT=1 ; Plus 'location_id' will assign the sale to the store/customer/employee where the sale was made. The php part will need to be changed, to reflect the new store/location setting. When employee is logged in he/she should be restricted to items/customers/sales that are assigned to this location/store.