<html>
<head>
<style>
span.courier {
  font-family: 'Courier', 'Courier New';
}
span.helvetica {
  font-family: 'Helvetica', 'Arial';
}
span.times {
  font-family: 'Times, 'Times New Roman';
}
span {
  font-size: 30px;
}
</style>
</head>
<body>
<p>
  You should see each font name in that font:
</p>
<span class="helvetica">HELVETICA</span>
<span class="courier">courier</span>
<span class="courier"><b>COURIER</b></span>
<span class="times">times</span>
</body>
</html>