AJAX Live Search with jQuery

AJAX Live Search with jQuery

Does jQuery has the ajax search ability? I mean if I press any key in a textfield in real-time it searches database and shows all entries matches that entered value, for example if I enter "ad", and database has both "admin" and "adela" it shows both in a list and allows you to select one, something log the search ability on wikipedia. Is it possible with jQuery? If yes, can you give me a direct link to the tutorial to do this?