how do i tske a screenshot on Windows Phone 8?

I couldn't figure out how to do it. I tried both home + camera and power + camera. None of them works.

Hold camera button. Tap windows key.

it just switch to camera right away. Arrrggg annoying key cursor miving atiund.I

Hold the power button + Windows Key.

doesn't work either.

Use the Power key and the start key at the same time:

Download this:http://websurfaces.co.uk/2012/11/11/nokia-lumia-920-user-guide/

@Ian2:

after several tries, it works. A lot of time it goes to voice command, but, with few more tries and good timing precision, I was able to capture the screen. It is difficult, but at leadt it works. Thank you for the help.