Attempting to make a "step-forum"

I have recently been trying to create a forums using SQL and PHP.

However, I have hit a roadblock.

I am trying to make, what I call, a step-forum but I am having some issues trying to come up with the code to get it to work.


Here is an example of what I'm trying to do.



A user makes a general post for people to respond to.

Then, a user makes a post in response and makes the title "post1".

Here's what the forum would look like:

post1




Next, another user makes a post to respond to "post1" called "post2".

Here's what the forum would look like:

post1
-post2


Another user makes a post to respond to "post1" called "post3".

Here's what the forum would look like:

post1
-post3
-post2



Then a user responds to the original forum post called "post4".

Here's what the forum would look like:

post4
post1
-post3
-post2



Now a user responds to "post3" called "post5".

Here's what the forum would look like:

post1
-post3
--post5
-post2
post4



After this a user responds to "post2" which bumps it up.
Let's call this "post6".

Here's what the forum would look like:

post1
-post2
--post6
-post3
--post5
post4



With each post made to a previous post, it is tabbed out thus creating a step-effect.

I don't really know how else to explain this.




Hopefully I can get a little help with this.
Thanks for your time,
SupermanDX

What you need is a threaded discussion (http://en.wikipedia.org/wiki/Threaded_discussion)