[NTG-context] Animations (again, but different)

Dear Contexters! In the last few days I could read a few posts about "animations" in a resulting PDF document. Some statements mentioned java script as possible means to create an animation. Is it possible to do the following (which is rather simple using html and javascript)? -- Have a bunch of thumbnail pictures -- When you click on a thumbnail you see a larger version of the same picture -- With the next mouseclick the picture vanishes (you see the gallery of thumbnails again) if yes, how? Any hints are welcome. kind regards Erik