Correct permissions to enable posting under subforums only

[MGadAllah]

Hello,

Please I'd like to know the correct permissions to enable posting under the subforums only and not the main forum root.

For example, Forum1 is the main forum and it has 2 subforums which are Forum-a and Forum-b.

How can I enable posting under Forum-a and Forum-b only and disable posting under the root of the main forum which is Forum1.

I hope that I made myself clear.

Also I do not want to have the search box or the There are no topics or posts in this forum statement.


Thanks
Mohamed


Note: I've tried to play with forum permissions but played with a lot of permissions and still can not make it correctly as the way I'd like to have.

[MGadAllah]

I've solved the problem. Just to make the forum as a category and then it is solved .
Thanks
Mohamed