How to resize an image to fit in the browser window?

Question

This seems trivial but after all the research and coding I can\'t get it to work. Conditions are:

1. The browser window size is unknown. So please don\'t propose

Answer 1

html, body{width: 99%; height: 99%; overflow: hidden}
img.fit{width: 100%; height: 100%;}

Or maybe check this out: http://css-tricks.com/how-to-resizeable-background-image/