.yellow_block {
    background: url("/images/yellow_block/center_top.jpg");
} 
.yellow_block div {
    background: url("/images/yellow_block/left_top.jpg") left top no-repeat;
}
.yellow_block div div {
    background: url("/images/yellow_block/right_top.jpg") right top no-repeat;
}
.yellow_block div div div {
    background: url("/images/yellow_block/right_bottom.jpg") right bottom no-repeat;
}
.yellow_block div div div div {
    background: url("/images/yellow_block/left_bottom.jpg") left bottom no-repeat;
}
.yellow_block div div div div div {
    background-position: 10000px 10000px;
    padding: 5px;
}