how to stop when two cubes are there...

check out the above pic. the player mechanics is moving one step up ,down ,left ,right.he can push one in free space. if there is two cubes he can't he has to stop at his position.

what am doing is do recasting on which way my player is moving(small amount) while he moving it is anything hitting am making that as a child to the player.and also whenever it is hitted am looling for any other guy is there with onemore racasting (this raycasting is done whenever the player is hitting to one guy, this for search any other guy is beside the child).

Problem

my raycasting can't detect the nother guy. how can do it.