19310 Autocomplete

In a form I want to put al kind of data in one field. I need a script using Ajax, PHP and mySQL that populates a autocomplete list using data from mySQL (more than 500 rows so maybe go to the db after filling in 2 or 3 char (dynamic)). eg. 'el' 'Delaey', 'Elaba', 'Kael' But the form need to have de id from the database and not the name