Expert Sokoban is a Sokoban game aimed at the expert: moving the pieces is considered a trivial enough task that it doesn't add to the value of the gameplay. The challenge is to work out where to move the pieces.
So don't be surprised that you can't move the Sokoban explicitly - instead remember to click on the pieces!
Expert Sokoban is available for free - see the Download section. Expert Sokoban has it's own website here: Expert Sokoban.
Note that Expert Sokoban is a joint project with Timwi.