My nikon d40x doesn't take pictures in lcd anymore?

My nikon d40x used to take pictures while using the lcd display, however i think i changed a setting and now i can only take a picture with the viewfinder and the lcd is black. Please anyone tell me how to fix this and revert it back to taking pictures on the lcd please

Actually your D40x does not have live view

What you may have had actuate is the instant review of your photo after taking the shot.

See page 50 of your user manual