Dear Hans, Thank you for a nice solution. It is really cool! I always wonder what is the limit of ConTeXt. But I think that I am using very small portion of it. Here I'd like to ask one more thing. I downloaded the example of "Euro symbol" animation. Both button "here" and "restart" worked fine. However, a new pdf file of Euro symbol animation which was madden by recompiling the source not properly working in my macbook. "here" button works fine while "restart" lost the position.(just blank window is appeared) I tried a similar step by step drawing and got the same situation. Is it a problem in my machine only? Mac OSX 10.6.4 ConTeXt ver: 2010.06.23 12:45 MKIV fmt: 2010.7.18 int: english/english - this is luatex, version beta-0.60.2-2010070117 Thank you for your help. Best regards, Dalyoung