Billy's Code

<html>
<head>
<script>
function clickMe() {
  var BodyElems = document.getElementsByTagName('body');
  var BodyTrac = BodyElems[0].getAttribute('class');
  var BodyClass = BodyTrac;
  alert(BodyClass);

  if (BodyClass == "yeah") {
    document.write("Good morning!");
  }
  else {
    document.write("Good day!");
  }

  return false;
}
</script>
</head>
<body class="yeah">
  Bob's your uncle.
 <a href="javascript:clickMe();">click</a>
</body>
</html>