The Zend Developer Zone has a new tutorial posted (from Vikram Vaswani) about adding in an auto-complete input field to your site. His example uses a PEAR class, Dojo and some components of the YUI libraries.

Fortunately, modern programming toolkits like Dojo provide ready-made widgets that have the necessary client-side functions for autocomplete. Add a little bit of server-side glue, in the form of a PHP script that talks to a database to generate valid suggestions, and enabling this functionality in a Web application now becomes a matter of hours, rather than days. In this article, I'll show you how to do this using three different libraries: PEAR HTML_QuickForm, YUI, and Dojo. Come on in, and find out more!

He shows how to combine Dojo, YUI and the HTML_QuickForm PEAR package to create a field that, based on what they enter into the input field, searches a database to find values in that table.