【3】/*レイアウトの設定*/

#header {
background: #0099CC;
height: 120px;
width: 800px;
margin: 0;
padding: 0;
}
#contents {
height: 400px;
width: 800px;
margin: 0;
padding: 0;
background:#FFFFFF;
}
#contents #sidenavi1 {
background:#FFFF99;
height: 400px;
width: 140px;
margin: 0 1em 0 0;
padding: 0;
float: left;
}
#contents #sidenavi2 {
background:#CCCCCC;
height: 400px;
width: 140px;
margin: 0 0 0 1em;
padding: 0;
float: right;
}
#footer {
background: #99CCFF;
height: 80px;
width: 800px;
margin: 0;
padding: 0;
}