do you think " hollywood cinemas has seperate trend for specific period of time"

I think they are. Recently I saw three movies which were based on the same theme. Zombies and Viruses attacking humans. " I Am Legend", " 28 Days Later", " 28 Weeks Later". All the three of them were based on the same concept and it kinda shocked me. I was confused and was wondering if one was copied from the other. Hope they have a better category of movies coming up.. I am bored of the new stuff that has come out. bourne

I think it's a case that if a film in a particular genre does well commercially, the suits in Hollywood dig out all the old scripts on similar themes that they've had lying around for ages, in the hope of repeating the success. So if someone makes a Western that does really well, they go through all the Western scripts that have been submitted over the last few years and filed away, and produce one of them with a big name star in it. If that also does well, you've got a trend, at least for a couple of years.