Dear Wolfgang, Thank you for the explanation, and your sample works nicely. I enclosed \processMPbuffer using \startframe and \stopframe as following. Then I got a 'undefined control sequence' error. If I use '\framed[]' instead of '\startframe … \stopframe', then it gave all 7 circles of different radius in two pages without error. If I add "\startanimation … \stopanimation", the only change is the appearance of menu at the bottom of the last circle.(no animation) What is wrong in the code? Best regards, Dalyoung Happy New Year to all listers!!! %%%%%%%%%%%% \startbuffer[circles] path p; numeric n, u; u := 1cm; n:=\recurselevel*u; p := fullcircle scaled n; draw p; \stopbuffer \usemodule[animation] \setupinteraction[state=start] \starttext %\startanimation[menu=yes] \dorecurse{7}{ \startframe % \framed[]%{\processMPbuffer[circles]}} \processMPbuffer[circles] \stopframe } %\stopanimation \stoptext %%%%%%%%%%%%%%%%%%%%%%%%%%%% ! Undefined control sequence. system > tex > error on line 23 in file test-ani.tex: Undefined control sequence ... 13 \setupinteraction[state=start] 14 15 \starttext 16 17 %\startanimation[menu=yes] 18 \dorecurse{7}{ 19 \startframe 20 % \framed[]%{\processMPbuffer[circles]}} 21 \processMPbuffer[circles] 22 \stopframe 23 >> } 24 %\stopanimation 25 26 \stoptext 27 \12>>1 #1#2-> \startframe \processMPbuffer [circles] \stopframe \syst_helpers_recurse_indeed_yes ...curse_content \syst_helpers_recurse_indeed <to be read again> { <inserted text> 2 \syst_helpers_recurse_indeed ...the \innerrecurse }{#2} l.23 }