Inline DIVs

HTML

<div class="relative">
    <div id="one"></div><div id="two"></div>
</div>

CSS

div.relative {
    position: relative;
    width: 500px;
    height: 500px;
    overflow: hidden;
    background: blue;
    white-space: nowrap;
}

div#one{
    position:relative;
    display: inline-block;
    width: 200px;
    height: 50px;
    margin-left:0;
    margin-right:auto;
}

div#two {
    position:relative;
    display: inline-block;
    width: 200px;
    height: 50px;
    margin-right:0;
    margin-right:auto;
}

div#one {
    background: red;
}

div#two {
    background: green;
}