.banner728, .banner468, .banner234 {margin-bottom: 40px;}
.banner728 {
    width: 728px;
}
.banner468 {
    width: 468px;
}
.banner234 {
    width: 234px;
}
.leftHome .banner728, .leftHome .banner468, .leftHome .banner234 {
    margin: 0 auto;
    margin-bottom: 40px;
}


@media screen and (min-width:1225px) {
    .banner728 {
        display: none
    }
    .banner468 {
        display: block
    }
    .banner234 {
        display: none
    }
}

@media screen and (min-width:1091px) and (max-width:1224px) {
    .banner728 {
        display: block
    }
    .banner468 {
        display: none
    }
    .banner234 {
        display: none
    }
}

@media screen and (min-width:840px) and (max-width:1090px) {
    .banner728 {
        display: none
    }
    .banner468 {
        display: block
    }
    .banner234 {
        display: none
    }
}

@media screen and  (max-width:839px) {
    .banner728 {
        display: none
    }
    .banner468 {
        display: none
    }
    .banner234 {
        display: block
    }
}