.bottom {
    height: 70px;
    margin-top: -70px;
}
.clear {
    clear: both;
}
.float_left {
    float:left;
}
.float_right {
    float:right;
}
.null {
    height: 10px;
}
.null2 {
    height: 30px;
}
.margin-top14px {
    margin-top:14px;
}
.margin-left15px {
    margin-left:15px;
}