I have a web site and i am showing videos to visitors, at the admin side i am filling the form of video and upload video file and sometimes i need to change(update) the video so i update the video by uploading another one, when i create the video in the first time i concatenate a datetime variable with the video name to avoid repeatition(file already exist) and when updatting the video the problem appears.... as if i upload the new video with the previous name so it will replace the previous one and in this case if the video is used by another process it will fail and the second option(which i am already using) is to upload a new video and concatenating new datetime variable with video title, so the previous and the new video will exist in the same directory and in this case i will lose too much space in my server directory as i have unused videos which takes space which in future will cause problem to me in the disk space so how can i solve this problem ?

Hope that my question is clear....thanks in advance for any try