Triple Database Combo

Hi, I know this issue has been raised quite alot around numerous usergroups and has been answered to an extend by some, but after a bit more than a week of struggling, I decided to post the question anyway. I have 3 comboboxes. The first combobox gets filled by a simple 'select' statement out of an Oracle database with php 3.0.16 (OCI calls), and is available when the page loads. After a selection is made on combo1, another query must be executed to fill values in combo2. Combo 2 choices is dependant on what is selected in combo 1. The query which fills combo2 uses a 'where' clause from combo1: ie. select 'value for combo2' from table where value = 'value selected in combo1' Similarly combo3 must be filled with a 'where' clause selected by combo2. I'm sure this must be possible, somehow. I have tried writing a combined query with all possible results and making an OCI call to write all values into an array, but it makes the query too big (linking 3 tables) and way too slow. The whole idea is not to have the page reload after every combo selection, but to have 3 dynamic selections. Any help would be much appreciated Pierre South Africa