Demo Size

HTML

<div id="wrap">
    <div class="center-page">
        <header>
            <nav id="main-menu">
                <ul class="clean">
                    <li><a href="#">Menu 1</a></li>
                    <li><a href="#">Menu 2</a></li>
                    <li><a href="#">Menu 2</a></li>
                    <li><a href="#">Menu 3</a></li>
                </ul>                
            </nav>                            
        </header>

        <div id="content">
            <h1>Content</h1>
        </div>
        <div class="clearfooter"></div>
    </div>
</div>
    
    
<footer>
    <div class="center-page">
        <h1>My Footer</h1>
    </div>
</footer>

CSS

html, body {
  height: 100%; }

#wrap {
  height: 100%;
  margin-bottom: -280px;
  position: relative;
  background-color: blue }
  #wrap > div {
    min-height: 100%;
    height: 100%;
    background-color: red; }
    #wrap > div > header {
      overflow: hidden;     
      background-color: yellow;    
      position: relative; }
      #wrap > div > header > img {
        float: left; }

#main-menu {
  width: 565px;
  height: 148px; }
  #main-menu > ul > li {
    float: left; }
    #main-menu > ul > li > a {
      display: block;
      padding: 3px 5px; }
  #main-menu > div {
    text-align: right;
    margin-right: 66px; }

.clearfooter {
  height: 280px;
  clear: both; }

#content {
  background-color: #ccc; }


ul.clean, ol.clean {
  margin-left: 0;
  padding-left: 0; }
  ul.clean li, ol.clean li {
    padding-left: 0;
    list-style-type: none; }
    ul.clean li ul li, ol.clean li ul li {
      list-style-type: none; }
      ul.clean li ul li ul li, ol.clean li ul li ul li {
        list-style-type: none; }

footer {
  background-color: green;
  position: fixed;
  bottom: 0;
  width: 100%;
  height: 280px;
  z-index: 999999; }

.two-columns {
  overflow: hidden;
  clear: both; }
  .two-columns > div:first-child {
    float: left; }
  .two-columns > div:last-child {
    float: right; }

.center-page {
  width: 940px;
  margin: 0 auto;
  overflow: hidden; }