The examples below used the following in the HEAD section of the document:

<SCRIPT LANGUAGE="Javascript" TYPE="text/javascript" SRC="plugins/overlib.js"></SCRIPT>
<SCRIPT LANGUAGE="Javascript" TYPE="text/javascript">
<!--
function myFunction() {
  var txt = ''
  txt += '<CENTER><FONT FACE="Arial, Helvetica, sans-serif">'
  txt += 'This is an <FONT COLOR="RED">EXAMPLE</FONT> of the <FONT COLOR="RED">FUNCTION</FONT> statement'
  txt += '</FONT></CENTER>'
  return txt
}
function myFunc2() {
  var txt = ''
  txt += '<CENTER><FONT FACE="Arial, Helvetica, sans-serif">'
  txt += '<B><I>myFunc2() call</I><B>'
  txt += '</FONT></CENTER>'
  return txt
}
//-->
</SCRIPT>

These examples do not have a default function defined. In this case, I've set the return string for the last example #4 to 'No Function' which will serve as a reminder that you didn't assign a default function just like seeing 'Default text' indicates that you haven't supplied any input string.