Vin> I'm trying to code an interactive function which I want to Vin> run under both XEmacs and FSFmacs. I want this function to Vin> maintain the region, so under XEmacs, I would use: Vin> (interactive "_") "_" is not a valid argument for Vin> (interactive) in FSFmacs, however, so how can I write this Vin> function? (defsubst folding-preserve-active-region () "In XEmacs keep the region alive. In Emacs do nothing." (if (boundp 'zmacs-region-stays) ;Keep regions alive (set 'zmacs-region-stays t))) ;use `set' to Quiet Emacs Byte Compiler (defun folding-forward-char (&optional arg) "Move point right ARG characters, skipping hidden folded regions. Moves left if ARG is negative. On reaching end of buffer, stop and signal error." (interactive "p") (folding-preserve-active-region) ... Gleb