nikon - How do I preview the look of my frame before taking the shot, on the LCD of my D5100 after altering the settings?

I just bought a Nikon d5100 and everything seems to be working pretty fine. Except for the fact that I am unable to preview the shot I'm willing to take. When I turn my LCD it shows me what the camera is seeing. But when I change settings like iso, f stop etc and try to see how it has affected my frame, the LCD just doesn't show it. It still shows me what my camera is seeing.

If there are any adjustments I need to make in the settings please let me now. I would like to see how the change in iso or f stops would affect my image even before I click like in Canon, on my LCD. The reason I'm stressing on the same point again and again is because someone asked this question earlier and most of the people who replied didn't understand the question.