How to keep the photo parvite for registed only photo

[mancool]

How to prevent the directly linking (image) show in public when such photos is for member or register only.

For Example,
http://www.myalbum.xxx/album/photofolder/01.jpg
The photo that in the catalogue and also is for member only. Then after logout, paste the direct linking to browser the photo. It works!? In case, someone know this link and he can guess the other photo's linking but sorting it directly. Is this have any method to prevent this thing happen!?

[Tranz]

http://coppermine-gallery.com/forum/index.php?topic=3021.msg45672#msg45672