Question : Help with centering this background image

Hi,
With this site here
http://amandawatson.com.au/alkaway/index.html

You will see there is a splash of water as the background image.

However its fixed to the top left of the site, and I want it to stay centered around the main image no matter what the width is.?

Can someone help me tweak the CSS to achieve this?

Answer : Help with centering this background image

background-position:center;

http://www.w3schools.com/css/pr_background-position.asp