The easiest way (that I can think of right now) to deal with accented characters would be to build some sort of translation table which specifies which ASCII character any given accented character should be converted to. For example, array('à' => 'a', 'é' => 'e' ... 'Ź' => 'Z'). There might be a lot of characters to consider but you'd only have to construct the translation table once.