by Reza Kowsari.
Thanks Ken,
Actually it's freewebhostingarea.com. Unfortunately, its forum is not available yet so I can't ask them about my problem. When I login the host and go to the file manager, there is nothing like public_html or any other directories. It looks like I'm already in public_html and can't go back to upper directories that moodledata normally should be there. So I have to place moodledata in web directory.
Is it possible to have moodledata in a web directory?