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 getWindowWidth() {
  var windowWidth = 0;
  if(typeof(window.innerWidth) == 'number') {
    windowWidth = window.innerWidth;
  }
  else {
    if(document.documentElement && document.documentElement.clientWidth) {
      windowWidth = document.documentElement.clientWidth;
    }
    else {
      if(document.body && document.body.clientWidth) {
        windowWidth = document.body.clientWidth;
      }
    }
  }
  return windowWidth;
}
    
function centreContent() {
  if(document.getElementById) {
    var offset = 30;
    var windowHeight = getWindowHeight();

    if(windowHeight > 0) {
      var contentElement = document.getElementById('wholepage');
      var contentHeight = contentElement.offsetHeight;
      if(windowHeight > contentHeight + offset) {
        contentElement.style.position = 'relative';
	contentElement.style.top = 
	  (windowHeight - contentHeight) / 2 - offset + 'px';
      }
      else {
        contentElement.style.position='static';
      }
    }
  }
}