how do i prevent a php script from being executed simultaneously?

i have an upload script and i would like to display an error message when a user uploads multiple files at a time.

any help would be appreciated.
techdaemon Reviewed by techdaemon on . prevent a php script from being executed simultaneously how do i prevent a php script from being executed simultaneously? i have an upload script and i would like to display an error message when a user uploads multiple files at a time. any help would be appreciated. Rating: 5