extraer(); if($_REQUEST['query'] !=null){ if($_REQUEST['type_book']!=null){ $books = new XMLBooksFiltered("Sira Vegas"); $books->extraer(); } if($_REQUEST['type_conference']!=null){ $conferences = new XMLConferencesFiltered("Sira Vegas"); $conferences->extraer(); } if($_REQUEST['type_journal']!=null){ $journals = new XMLJournalsFiltered("Sira Vegas"); $journals->extraer(); } } ?>