My Bluetooth keyboard doesn't connect?

My bluetooth wireless keyboard for my iMac 24" doesn't connect anymore. Last night it was working fine and when I tried to use it today at the login screen it didn't connect. The light on the keyboard is blinking and then if I don't do anything it turns off. I've tried going into the bluetooth settings and then setting it up but it doesn't even show up in the bluetooth options. I've turned it off and then tried it too by tapping the power button, but the bluetooth device isn't even recognized in the bluetooth search so I can't even set it up. I've tried resetting the Mac also. Right now I'm using a regular USB keyboard so it doesn't have any of the Apple specific keyboard keys on it that I can use for commands. I don't know what to do I even searched the help articles but they don't help... I can't get it to show up AT ALL in the bluetooth setup no matter what I do, my trackpad however, does work and is shown, I've even turned bluetooth on and off again. Thanks for any help...