Apple is now requiring in-store iPhone 4S wanna-be buyers to reserve their iPhone 4S a day ahead of time.

However, as of Monday evening, Apple’s reservation system is not working.

On Apple’s “How To Buy” page, at apple.com/iphone/how-to-buy, there is now a button for reserving an iPhone. The instructions say that the “iPhone 4S is available in store by reservation only. Reserve yours after 9:00 p.m. tonight for pickup tomorrow.”

Apple goes on to say that the buyer can choose the carrier and plan when they come to pick up the phone, and that Apple will get the iPhone 4S set up and running before the customer leaves the store.

According to AppleInsider.com, the reservation system is set up in such a way that only the number of phones available the following day will be able to be reserved. This will eliminate customers arriving at an Apple store only to be sent away empty handed.

But here’s the rub, at least right now – once a user clicks on the reservation button, they get to a page saying that the phones are available for reservation on a first come, first-served, basis. The user is then asked to select a location. There are two drop down boxes presumably for this purpose – but are both blank and nothing is selectable.

We tested using both MSIE and Chrome, from three different computers in two different locations. No joy on any of them.

The reservation system, working or not, does not affect online iPhone 4S sales placed through Apple, nor sales through carrier stores and websites.

—-update—-

Apple’s reservation system now appears to be functioning. States and stores appear and are selectable in the drop down menu.