body {
background: url(../img/sideimage1.jpg) no-repeat center center fixed;
-webkit-background-size: cover;
-moz-background-size: cover;
-o-background-size: cover;
background-size: cover;
font-family: ‘Times New Roman’, Times, serif;
line-height: 180%;
font-size: 14pt;
color: #000;
}
I used the cover attribute in CSS3 to make the image cover the whole screen no matter what. It only works in new browsers though, but honestly people should be updating their browsers anyways 