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('container');
          var contentHeight = contentElement.offsetHeight;
          if (windowHeight - contentHeight > 0) {
            contentElement.style.position = 'relative';
            contentElement.style.top = ((windowHeight / 2) - (contentHeight / 2)) + 'px';
          }

        }
      }
    }
    window.onload = function() {
      setContent();
    }
    window.onresize = function() {
      setContent();
    }