<style>
.c1 {
background: none repeat scroll 0 0 #FF0000;
height: 100px;
position: absolute;
width: 100%;
}
.c2 {
background: none repeat scroll 0 0 #000000;
height: 400px;
position: absolute;
width: 100%;
}
</style>
<div class="c1">sdsdsds</div>
<div class="c2">sdfsd</div>