Ritesh, I started working with a canvas script a few months back with jquery (can't remember the author, but if you do a search for canvas in the group, i am sure you will find it) and the problem was that when the drawing became to complicated it started slowing the browser down drastically. So i resorted to a flash/javascript combination.
-- Benjamin Sterling http://www.KenzoMedia.com http://www.KenzoHosting.com