php regexp question

hi i've made a small php site that is searching against french documents stored in a mysql database. when it comes to rendering search results, the client has asked if the words that were searched for can be highlighted. "no problem!" i thought. just do a regexp replace and wrap a <b> tag around the matching terms. then i realised that the following would not produce a match: $string = "Françoise"; echo preg_match("/francoise/i",$string); so my question.... since mysql managed to produce a match here, is there perhaps a php regexp modifier that (maybe) knows how to make this match? thanks