Bricks, Masonry, Asphalt and Concrete - brick question

I am soon to begin my next project of building an outdoor fire pit. have a couple of cubby holes planned to store firewood and such. my question is....how do you set the top layer or brick? I will try to provide a scetch using my keyboard:


_ _ _ _ _ _ <-- this is the top
|.............| <-- this would be one side. "." is blank space.
_ _ _ _ _ _ <-- this is the bottom.

as you can see by my picaso of a rendition...it is pretty much just a box. I know how to set brick and all but it only goes as far a wall where the lay flat on one another. now i am dealing with an opening an not sure how to do it support wise?

man i hope i explained that good enough.

thx as always.

Use an appropriate steel lintel to go over the opening and set the bricks on that.
Frank