Regular expression

Simple reg help please i want to match the last "," in "a,b,c,d" and replace it with " and " i tried ereg_replace(",([a-zA-z])*$"," and ",$string); but i forgot how to add the "d" which is also matched now back to the " and " Can you give any good reg_exp sites where to learn it? Its long ago since i used reg exp and i lost the hang of it... :( btw. any sites that have reg_exp that works witht PHP would be fine. i know http://www.regular-expressions.info/tutorial.html But that examples dont work with preg_match and ereg. Thanks ^_^ -- Smileys rule (cX.x)C --o(^_^o)