Patrice: > The attached code is an animation describing digital communication. > When compiled in a classical document then the pdf is perfect. I tried this PDF - very cool! So I ran the LaTeX code you supplied and, after installing animate.sty and animfp.sty got this error: ! Undefined control sequence. <argument> \OR l.325 ...se{\boolean{pdf}\OR\boolean{@anim@xetex}} { What's missing? Thanks, Tom Dr. Thomas D. Schneider, Ph.D. National Institutes of Health 240-367-4179 (cell) schneidt@xxxxxxxxxxxx toms@xxxxxxxxxxxx (permanent) http://alum.mit.edu/www/toms (permanent)