.bannerpic{}
.b_top, #b_top{width:728px; height:90px; float:right;}
.b_righttop, #b_righttop{width:120px; height:400px; float:right }
.b_rightbottom, #b_rightbottom{width:120px;height:240px ;float:right }
.b_lefttop, #b_lefttop { width:120px; height:400px; float:left}
.b_leftbottom, #b_leftbottom {width:120px; height:240px; float:left }
.b_bottom, #b_bottom {width:728px;height:90px; float:right}