I'm trying to achieve something like this <http://jsfiddle.net/Zex4S/1/> so when you resize the window, it image keeps its aspect ratio, but at the same time, I don't want the height of this image to change, it must remain constant, and zoom in if necessary. 

I think it involves cropping the top and left margin, but I can't get it working

Something like this `$this.css('margin-left', ($window.width() - this.width) / 2);`

Any help would be greatly appreciated!