function getWindowHeight() {
          var windowHeight = 0;
          if (typeof(window.innerHeight) == 'number') {
            windowHeight = window.innerHeight;
          }
          else {
            if (document.documentElement && document.documentElement.clientHeight) {
              windowHeight = document.documentElement.clientHeight;
            }
            else {
              if (document.body && document.body.clientHeight) {
                windowHeight = document.body.clientHeight;
              }
            }
          }
          return windowHeight;
        }
        function setContent() {
          if (document.getElementById) {
            var windowHeight = getWindowHeight();
            if (windowHeight > 0) {
              var contentElement = document.getElementById('content');
              var contentHeight = contentElement.offsetHeight;
              if (windowHeight - contentHeight > 0) {
                contentElement.style.position = 'relative';
                contentElement.style.top = ((windowHeight / 2) - (contentHeight / 2)) + 'px';
              }
              else {
                contentElement.style.position = 'static';
              }
            }
          }
        }
        window.onload = function() {
          setContent();
        }
        window.onresize = function() {
          setContent();
        }