The wires come from the midpoints of the screen edges.
Let's say you connect left and bottom to ground and right and top to +5V and the resistors are 500 ohm. Touching the center will give a left-right and top bottom value of 500.
I'm gonna test that soon then.
Many thanx for your help gentlemen
I'll update the post when this is done...
Oh, and by the way, I found the references:
touchscreen Multitouch 10641 A.