Full browser sized background images

Hi All,
I have created a cross-browser technique of dynamically setting any kind of image to fill the entire size of a person browser window. The image scales proportionally should the browser window alterations and remains within a fixed postion when the page content scrolls upward or down.
I have definitely not found anything on the internet that ticks almost all these boxes, but this indicates to fulfil a common need for creative designers. Please take a hunt and let me find out what you think: http: //www. theblackotter. com/backdrop. php
Every little thing is Open Reference and free in order to download and use without restriction.
Oliver.