users sees the files uploaded by other users

[R.]

Hello,

My web site uses $_SESSION variables and session_start() to handle logins of different users. 

I use the JQuery FileUpload plugin on my webpage index_upload.php and it works.

If the user1 loads the index_upload.php file and uploads some files, it works. But after that, the user2 who loads the page sees the files uploaded by user1...

I don't want this : I want that user1 only sees the files he had uploaded himself...

Is there a way to do this ? 

Many thanks in advance ! 

R.