My boyfriend and I went to get into his mazda speedprotege tonight... he used his keyring to unlock the car and it was fine. As he put the key into the ignition and turned it nothing happened. No sound whatsoever and when we got out of the car his lock/unlock button on his keyring wouldn't work either. The battery is relatively new, so he doesn't see that as being the problem. Anyone have any suggestions of what it could be or how to fix this problem? Tomorrows thanksgiving and we can't go home with a dead car :(

. Place battery on a charger to confirm its status. Clean battery terminals and cable connections.

. Check all under-dash and under-hood fuses with a test light or multimeter:

https://www.askmehelpdesk.com/cars-trucks/faq-how-troubleshoot-repair-maintain-hondas-46563-3.html#post252145

. This may also help:

https://www.askmehelpdesk.com/cars-trucks/faq-how-troubleshoot-repair-maintain-hondas-46563-3.html#post235560

It seems like a simple connection at the battery post. Just make sure they're tight and cannot 'twist' them.
If the new batt is run down already, then something has caused a draw on it like a light left on. A bad alt will be the last thing.