A common port wall is the wall that is shared by the port and the box. In other words, its the bottom side of the port you in the box you drew. Hope you can understand what I'm explaining. If you are like me, words are hard to visualize and I always need a picture...if so, let me know. I can post a pic up of a box with one, two, and three common port walls.
Could you do that for me actually? Because now I am confused. I also think I have made a few boxed wrong now.......
picture now!!!! and so i did the common port walls wrong? if so how many do i have?