Displaying Forum Threads

Hi folks, I working on writing a discussion forum for my site. I've looked at several of the discussion boards offered at hotscripts.com and none of them offers exactly what I want. I've borrowed heavily from them, but the one thing I can't figure out (I'm really an idiot) is how they properly display the messages in a thread. I want the output to look like: First message -reply to 1st --reply to 2nd ---reply to 3rd -another reply to 1st New Thread -reply to new thread --reply to reply each "-" I'm going to replace with an image or something cool. I'm not sure how I should store the thread info in the MySQL database or properly extract it and use it. Any suggestions would be greatly appreciated. Thanks, -Tom