.thumbnails {
    width:512px; margin: auto;
    border-style:solid; background-color: grey;
    background-image: url("http://devfiles.myopera.com/articles/22/banner-background.jpg");
}
img.thumb { 
    width: 100px; height: 75px; margin: 5px; 
    border-style: solid; border-color: blue;
}
div.preview {
    width:512px; height:384px; margin: auto;
    border-style:solid; background-color: lightgrey;
}
img.the_preview { width:512px; }