body {
    background-image: url(images/back_all.gif); /** Link to the image you created **/
    background-repeat: repeat-y; /** Repeats the image vertically **/
    background-position: center; /** Centers the Background image **/
    background-color: #ffffff; /** Website BG colour  **/
}

#container {
    width: 768px;
    margin: 0 auto;
    text-align: center;
}