adding and removing the "responsive" class to topnav when the user clicks on the icon */
    function topNavFunction() {
      var x = document.getElementById("myTopnav");
      if (x.className === "topnav") {
	x.className += " responsive";
      } else {
	x.className = "topnav";
      }
    }
    function onBodyLoad() {
      var h = window.innerHeight
	|| document.documentElement.clientHeight
	|| document.body.clientHeight;
      document.getElementsByName("iframe_a")[0].height = h - 68;
    }
  </script>