thanks for your reply,
I post this topic to Php forums now.
Regarding your answer, I know it is big file and i ask my users to not upload. but sometime people dont read statement and just upload. I think, good thing is to add functionality. Usually when I upload image it reduce smaller size and then store.
I also want to learn this because many people ask me to do this.

thanks for reply
this thread is now in php forum as well