TP Dispenser Alarm

We all know the feeling. The job is done, time to start to clean the bottom and Whoa! No TP! Time to start screaming at the top of our lungs and declare our predicament to the world in the hopes that someone will help. I propose a simple solution. The toilet paper dispenser has two rolls, both normally filled, and only one available for access. when one is emptied, it falls down and is replaced by the one above it at the press of a button. This Button activates an alarm that warns you loudly every time you open the bathroom door, "WARNING: LOW TP!" until you replace the backup roll.