Illustrator - Joining two rectangle with a line in between

I am trying to join two shapes (figure - a) in Illustrator, And I want the effect should be like this (figure - b). I tried Unite option in Pathfinder, but that makes a big rectangle.

Attachment 96294

Please note: after joining I want one middle cut inside the rectangle.

Any idea?

Thanks.

I don't know the ultimate purpose and so the below may not apply.

Abut the two squares. Select both. Make a compound path of the two squares from the Object menu (ctrl + 8).

Take care, Mike

Attachment 96302

I wanted to make a logo looking like figure A, in doing so, I had to draw 3 triangle (figure B) and move them as close as possible and adjust them.

I could have drawn the outline of the shape of my logo and used line tool. But I want to shad those three segments in different colors. I could not shade three parts unless they have separators in between.

Is there any way in Illustrator to make those triangle and then join them together so in between lines are fixed?

I tried making compound path in object menu, but direct selection tool still can separate them :(

I just drew half a dozen lines with the pen tool then used the Live Paint tool (K) to fill in the parts that overlapped.
This may be the way to approach what you want to do.
Bob.
EDIT: I then drew a shape over the parts I wanted and then selected everything and in the Object Menu chose Clipping Mask> Make to hide the unwanted line parts.

Why are you trying to complicate things?
1. Just use the Pen Tool and draw the 3 shapes. If you worried about the lines at the mitre join just go to Outline (ctrl+Y) and then you will be able to make sure that the line converge on top of each other.
2. If you are working from a full shape remember you have the Scissor Tool and you could break apart at the join and then use the Pen Tool to join up the broken areas.

To use Illustrator properly you must learn to use the Pen Tool it is a must. Sorry if I have not answered your question but it seems to me so simple.