Tokenizing Strings

I have a string that needs to be split/tokenized based on a delimiter. This can easily be accomplished using 'break' if the delimiter is only 1 character (i.e. break isSpace "this is a string"), but I can't see any way of using this for a delimiter with multiple characters. in this case, I have a string containing multiples fields seperated by *two* blank lines (\n\n). I can't just break on the newline character, as single newline characters can be found inside each field. any idea how I can do this without too much hassle? -James (jamesd@mena.org.au)