.ads {
    border: 1px solid #000000;
    width: 325px;
    height: 125px;
}
#left {
    float: left;
    margin-left: 10px;
    width: 350px;
    
}
#center {
    margin-left: 355px;
    width: 350px;
}
#right {
    margin: 0 100px 0 0;
    float: right;
    
}