Background image will not stretch in ie7

I am using the following css to stretch and display a background banner along the bottom of the screen for the entire application:

/* This is used for the main login screen */
.v-verticallayout-homepage {
background: url(img/mandg-logos/city-scape.png) bottom left no-repeat;
width: 100%;
position: fixed;
background-position-x: 0%;
background-position-y: 100%;
background-position-z: -999;
background-size: 100%; width 100%;
background-color: white;
min-width: 100%;
color: black;

It works well in firefox, ie9 and chrome but ie7 does not stretch the image. I have read around the topic but people seem to suggest it cannot be done with css and must be done with javascript. I’m afraid I am not too hot on java script. Any help much appreciated.

An example of the issue can be found here: