Attach the POWER White wire to the LIGHT White........
Attach the POWER Black to the Switch White wire....(power to the switch)....the ends of the White wire in the "switch Loop" should be marked "Black"....Felt tip/paint.....
The SWITCH Black wire connects to the LIGHT Black.......(switched power from the switch)
The BLACK wire is always interrupted by the switch........The Neutral wire is NEVER switched.........