#header {
position:absolute; left:0px;
top:0px; width:640px; height:100px;
z-index:1; background-color: #FF00FF;
}

#leftbox {
position:absolute;
left:0px;
top:101px;
width:140px;
height:180px;
z-index:2;
background-color: #00FFFF;
}

#rightbox {
position:absolute;
left:140px;
top:101px;
width:500px;
height:180px;
z-index:3;
background-color: #FFFF00;
}

#footer {
position:absolute; left:0px;
top:281px; width:640px; height:120px;
z-index:4; background-color: #0000FF;
}