If I had those wires this is how I would have done it:
red for the hallway into terminal marked "com", black into L1
Short bit of wire between 2 terminals marked "com"
Red and black for the stars into L1 and L2.
If you need to find out which cable is which:
Connect the black and red together in one of the terminals of the switch
Turn the power back on; if the wires you have connected are for the hallway the hallway light will be permanently on, if it is for the stairs neither will be on.
Adam
February 2009