We have the following form:

Information about the author - field list_user ( title -"Author") type "user" is stored in the database “*_cck_store_item_content” only as ID (where ID = the ID of the table “*_user” Joomla users) /

Information about the co-authors – field fieldx_user (tiyle "Co-Author" ) type “field x” stored in “*_cck_store_item_content” AS “:: user | 0 | fieldx_user :: USER NAME :: / user | 0 | fieldx_user ::”

How to create a search on the first name / second name of the author/coauthors (USER NAME in table “*_user” and ) in table in if the table “*_cck_store_item_content” stored only author ID.