Actor-filmmaker Kamal Haasan, who has been recovering from a leg injury, has started working on his upcoming trilingual comedy "Sabash Naidu". He says he's happy with the progress and thanks well-wishers and physiotherapists."Started paper work again on Kundu/Naidu. Walking now. Ready to run show again. Mind is flying, gaining altitude. Good enough a progression," Haasan wrote on Twitter. In July, Haasan slipped and fell from his office stairs, resulting in two fractures on his leg. After spending nearly a month in the hospital, he was discharged.Haasan is playing the lead as well as directing "Sabash Naidu", which is simultaneously being shot in Telugu and Hindi.A spin-off based on the character Sabash Naidu from Tamil action-comedy "Dasavathaaram", the project also stars Shruti Haasan, Ramya Krishnan, Brahmanandam and Saurabh Shukla.