"Ronald" == Ronald van Engelen <ronalde@xs4all.nl> writes: Ronald> Hi, when I try to use the mouse wheel in Xemacs21 (tried Ronald> gnome/mule and other variants) I get a button4 not defined Ronald> error. However in other X apps and even in Emacs it works Ronald> just fine. Did you (require 'mwheel) and (mwheel-install)? /Shyamal