deny user to delete a file

Question

hi everyone,
in my project i want to deny users to delete my log file (x.txt) i searched but i couldnt get any answer about this topic in this forum.
in fact, my subject is that, i will create a file as a log file (X.txt). If i want to delete it i will set a specific property such as "canDelete" as True, it will be allowed to delete from anybody, how ever if i set canDelete=False, nobody will delete it.
is it possible?
waiting you suggestions,
thanx