Nikon D40- Light level settings?

In all of my photos, I can see what looks like a chart with the light levels. It's only there when I view the pictures on the camera (not when I upload them to my computer), so it's more of an annoyance than anything. You'll see the picture in the background, then a red outlined box with scribbly yellow waves (more like mountains) in the foreground, which make it very hard to see the picture. Does anyone know how I can turn this setting off? I've tried everything I can think of and my manual is hundreds of miles away.

Use the up and down buttons (around the ok button).

First you can download a user manual from Nikon and since it is an Adobe Acrobat file you can search for various features using "Find"

Second what you are seeing is called a histogram and it will also show up when you use the levels feature in Photoshop

Once you download your user manual, look on page 51 and 52 to select what you want your image review to show

It's called the histogram and it gives you an indication of where the highlights and shadows fall, so its a reasonable guide to a correct exposure.

if you want to turn it off, press the multiselector button (try up/down first) - if this doesn't work try left/right. It varies between Nikon models.