Filmmaker Mani Ratnam on Monday said he would like to extend heartfelt gratitude to the Indian armed forces through his forthcoming Tamil romantic drama "Kaatru Veliyidai".In "Kaatru Veliyidai", which is slated for April 7 release, Karthi plays a fighter pilot in the India Air Force."It's an intense love story shot against the backdrop of the Indian Air Force," Ratnam told reporters here at his film's audio launch."When we were shooting in Kashmir and Ladakh, I was astonished by the work of the Indian armed forces, especially their sacrifices for our country. I would like to extend gratitude to all of them through this film," he said.Ratnam said Air Marshal Simhakutty Varthaman (Retd) helped him through the making of the film.Talking at the event, Varthaman said: "I have always felt that the story about the Indian Air Force was missing on celluloid. When I learnt about this project, I wanted to lend my support. But never in my wildest dreams had I thought that I would be associated with a Mani Ratnam film."Varthaman hopes the film will awaken audiences and earn recognition for the Indian Air Force.Produced by Sri Thenandal Films, the film has music by A.R. Rahman and cinematography by Ravi Varman.