.main_container {
    width:940px;
    margin-left:auto;
    margin-right:auto;
}
.mid_container {
    margin:20px 0px;
}
.main_content_area {
    float:left;
    width:700px;
}
.right_sidebar {
    float:right;
    width: 220px;
}
.main_content_area,
.right_sidebar,
.footer,
.header {
    border:1px solid #bbb;
}