body{padding: 0; margin: 0 auto; background: url(background.gif) repeat-y fixed 50% 0%; overflow: auto; text-align: center; width: 920px; height: 100%;} 
#main{display: block; padding: 10px 10px 10px 10px; position: absolute; top: 0; clear: both; background-image: url('images/wood.jpg'); background-position: 50% 0%; margin: 0 auto; width: 900px; height: 100%;}