PHP webservice

I need someone to write a simple PHP based Webservice. The webservice will be hosted on 1and1 and will require: * The webservice will authenticate the posting application with a username and passsword * An application will then be able to post data to the webservice, e.g. named pairs of information - send category name & a value * The webservice will store the posted data in a MySQL database * The webservice will return either XML or JSON formatted data depending on an additional parameter the calling application sends. The response will either be a simple 'OK' response or if data is requested, a named pair of data. * There should be 3 methods in the webservice: 1. Login (application to send username/password) 2. Post data (application to send authenticated login token and the category of data to post along with the value of the data, webservice to store the data in MySQL and respond with an acknowledgement) 3. Request data (application to send authenticated login token along with the category of information requested, webservice to return the data stored in the database) * PHP version is 5.2 * MySQL is version 5 UTF-8 Deliverables to include: PHP Webservice MySQL schema / SQL file to build tables - tables to include Users and Data