I am wondering how I could set the background image to keep its position on this site: http://www.jylkkari.fi/wordpress/
When you drag the browser under 960 px wide, the background of sidebar starts to move towards center.
I found out this Javascript which could solve this problem.
I am still searching if there is a easy way in CSS to keep the image centered while browser width is more than 960 px and on fixed while it is under this size?