Autocast animated overlay trouble

[kez717]

I am in need of a way to use or mimic the default autocast animated overlay (like on pet buttons). My code is in only lua, no xml. I don't have anything related to autocast in my code at the moment, every attempt resulted in various errors (over 40 attempts (with lfg "eye", autocast shine, autocast sparkles, both the bits to get them to work on my buttons and the animation parts themselves modified to directly take a button)so a lot of errors) and I ended up removing it so get on with the rest of the addon. Either a script that copies the look of the animation that I can plug my buttons into (and how to use is) or info on what I data I need (and what format to put it in) so that my buttons will play nice with blizzards default animation would be appreciated. I've puzzled out the rest of the addon I'm working on (new to lua, only started about 2-3 weeks ago), but this just doesn't seem to want to work.