function getPageDimensions()
{
  var body = document.getElementsByTagName("body")[0];
  var bodyOffsetWidth = 0;
  var bodyOffsetHeight = 0;
  var bodyScrollWidth = 0;
  var bodyScrollHeight = 0;
  var pageDimensions = [0, 0];

  if (typeof document.documentElement != "undefined" &&
      typeof document.documentElement.scrollWidth != "undefined")
  {
    pageDimensions[0] = document.documentElement.scrollWidth;
    pageDimensions[1] = document.documentElement.scrollHeight;
  }

  bodyOffsetWidth = body.offsetWidth;
  bodyOffsetHeight = body.offsetHeight;
  bodyScrollWidth = body.scrollWidth;
  bodyScrollHeight = body.scrollHeight;

  if (bodyOffsetWidth > pageDimensions[0])
  {
    pageDimensions[0] = bodyOffsetWidth;
  }

  if (bodyOffsetHeight > pageDimensions[1])
  {
    pageDimensions[1] = bodyOffsetHeight;
  }

  if (bodyScrollWidth > pageDimensions[0])
  {
    pageDimensions[0] = bodyScrollWidth;
  }

  if (bodyScrollHeight > pageDimensions[1])
  {
    pageDimensions[1] = bodyScrollHeight;
  }

  return pageDimensions;
}


function getViewportSize()
{
  var size = [0,0];

  if (typeof window.innerWidth != 'undefined')
  {
    size = [
        window.innerWidth,
        window.innerHeight
    ];
  }
  else if (typeof document.documentElement != 'undefined'
      && typeof document.documentElement.clientWidth != 'undefined'
      && document.documentElement.clientWidth != 0)
  {
    size = [
        document.documentElement.clientWidth,
        document.documentElement.clientHeight
    ];
  }
  else
  {
    size = [
        document.getElementsByTagName('body')[0].clientWidth,
        document.getElementsByTagName('body')[0].clientHeight
    ];
  }

  return size;
}