backgound image not large enough??!!

I use a paining as the backgound image outside my store. Because I have a extra-large size monitor, I found out the painting doesn't stretch into the whole screen, leaving the right side of the store empty. It looks very funny....

I tried all kinds of codes in the stylesheet, but no luck. would you please take a look at my site (https://www.thesbeauty.com) and advise me how to fix it? thanks!!!

Here is my code:
body {
margin: 0px;
font-family: Verdana, Arial, sans-serif;
font-size: 63.75%;
color: #333333;
background-image: url(../images/bg.jpg);
background-repeat:no-repeat;
background-attachment: fixed;
height: 110%;
width: 100%;
left: 0px;
top: 0px;
z-index: 0}

Navigating directly to your image produces a not found error

http: //www.thesbeauty.com/includes/templates/classic/images/bg.jpg

Plus I did not see any background image

Since the site is an alive site. I changed the backgound image to background color temporily (it really looks ugly with the imcopletely background image). But I will still like to get advice!

I changed the backgound image to background color temporily
And removed the image also???