<style type="text/css">
html,body{
height:100%;}
#box {
100%;
height:100%;}
.one{
100%;
height:100%;
background:url(images/02.png) no-repeat top center fixed;
background-size:contain;
}
.two{
100%;
height:100%;
background:url(images/drinkzeo.png) no-repeat top center fixed;
background-size:contain;}
</style>
</head>
<body>
<div id="box">
<div class="one">1</div>
<div class="two">2</div>
</div>