.mainBox{width:960px;
????????height:300px;
????????background-color:#CFF;
????}
.leftBox{
????width:740px;
????height:300px;
????background-color:#C9F;
????float:left;
}
.rightBox{
????width:210px;
????height:300px;
????background-color:#FCF;
????float:right;
????
}