permissions question

[Sman1400]

How can i make it so that members can view a Board's exsistance on the index, but not the list of topics on that board

for example, say i have a board called "You Need 15 Posts to view this board", and when you click it, if you have under 15 posts, it will say you lack permissions to view this board, ive seen it done on some forums

i just want new members to be able to know of certain board's exsistances but not be able to post there or view topics until they have met the requirements, cant seem to figure it out

[SoLoGHoST]

If you want people to know of boards existence, but boards have certain requirements before they can access these boards, would be easier to just post this either upon registering for members, or someplace else.  Something like: 

The following boards will be viewable when the following requirements are met:

1. Cool Board - You Need 15 Posts to view this board.
2. Cooler Board - You Need 45 Posts to view this board.
3. Coolest Board - You Need 150 Posts to view this board.

Well, would be easier in my opinion.

[Sman1400]

well i do have that now, but ive seen it done before so i kinda of want it but i just cant figure out how must be a mod

EDIT: figured it out its a mod

http://custom.simplemachines.org/mods/index.php?mod=610