plotyy exists in 3.0.x and should give better results than this.. However a fully working plotyy is only available in the 3.1.x for various technical reasons D. -- David Bateman dbateman at dbateman.org 35 rue Gambetta +33 1 46 04 02 18 (Home) 92100 Boulogne-Billancourt FRANCE +33 6 72 01 06 33 (Mob)