If you want to add an image that resizes according to the monitor or the browser size just follow the steps:
First put the image exactly after the opening <body> tag:
<body>
<img src=”images/bg.jpg” class=”bg” />
Then go to the CSS and add this:
img.bg {
bottom:0;
min-width:1024px;
position:fixed;
right:0;
width:100%;
}
Then add some exception CSS for IE6, because it doesn’t get this stuff to work well.