After taken photos the image out of focus - Nikon D80 Digital Camera with 18-135mm Lens

On the front of the camera body, below the lens release button you should find a two position switch labeled "AF" & "M" This is the "Auto Focus - Manual" selector switch. Make sure the selector is set to "AF" for auto focusing.

Your lens may have a similar focus selector switch on its barrel. There are two types of switches used - depending on the lens. The first is labeled "M/A" and "M" The "M/A" position indicates it is in "Auto Focus" mode with a "Manual" focus over ride capability. You can simply twist the focus ring to change the focus to a point other than that chosen by the camera's auto focus system. The "M" position is Manual Focus mode. No focusing operations will be performed by the D80 auto focus system - focusing must be done by the photographer.

The second type has "A" & "M" positions. These represent Auto and Manual focus. The difference between this type switch and the "A/M & "M" switch is that when in "A", the camera will no allow the focus to be changed manually. There will be opposition to twisting the focus ring in the position. Forcing it will likely result in damage. The selector switch must be changed to "M" to change the focus.

If either switch is set to manual, the auto focus system will be disabled, so it is very important to have them both set to "A" or "A/M".

I hope this helps. Please rate my reply - thanks!