Guys, The PDB file format is proving hard to crack. By far, it's the most difficult format I've had to deal with. Genbank only comes second. There's a new format mmCIF to eventually replace PDB, but since I'm halfway through PDB, I might as well continue it... but only after... A ONE WEEK BREAK FROM BIOPHP/GENEPHP... ARGGHH!!!!! See you next week! =) Regards, Serge Need a new email address that people can remember Check out the new EudoraMail at http://www.eudoramail.com