i have the paint tool sai free trial, but it expired. i am working on a drawing but its not finished. it won't let me save and if i save it as a regular file then i won't have my layers any more. is there a way that i can save it as a sai document so that i can open it on sai and work on it once i buy it? will it still have the layers? please help. i don't wan't to lose all my progress. also, if i delete the sai program i have, will it let me download a new trial?