Add upload .flv capability to ffmpeg script

I have a video sharing script running ffmpeg and ffmpeg-php. The script allows a file to be uploaded (wmv, mov, avi, etc..) and then converts it into a .flv and stores info to the database. The script does not allow for .flv to be uploaded. I need the ability to upload .flv. This should be a simple project for someone that is fluent in PHP5.