NTFS permissions

I have a NT4 SBS server with 20 users. i am trying to allow users to create new files and directories, edit the existing files but not delete anything. the problem is if i give read and write but not delete. then the users can still delete files that they are the owner of. and also a lot of temp files are left behind. is there a way around this without having to take aownership, and getting a user with permission to delete all the temp files. I know that in 2000 onwards there is a permission to allow change.