Algodoo

hope this helps... measures the x distance of bothe objects.
the box in the middle is the distance...
the lasers have the scripts:
{scene.my.v1 = e.pos(0)} {scene.my.v2 = e.pos(0)}
this saves the x-position of the boxes in e.pos
the box in the middle has:
{"" + {scene.my.v1 + scene.my.v2}}
i think ( ) is right too...
to measure thy Y-distance change the scripts on the laser to e.pos(1)
if you will have x and y coordinates then remove the (0) behind e.pos


best regards bluebravo