Nikon d40 won't turn off?

I discovered it recently and am not sure how long it's been like this, but my nikon d40 won't turn off. I tried resetting the settings and taking out the batteries. Nothing happens. I flip the switch on off, the camera still thinks it's on. Everything else works fine though.

Can anyone help.please!

Actually no we can't help. Sounds like a job for Nikon. I'd suspect they'll want the camera and they'll probably replace the power switch. It will cost you so perhaps get an estimate before sending it to them.