The background image is getting fetched from the CSS file.
Which means: If your CSS file is located in /Home/style.css and that your background is located at /Home/bg.png, you must specify the following:
background-image url("bg.png");
or:
background-image url("/Home/bg.png");
If the file is located at /bg.png and that your only a folder deep (for example, if your stylesheet is located at /Home/style.css), you can tell the stylesheet to climb up a folder, and then fetch the background, like so:
background-image url("../bg.png");
Hope this helps.