Untitled

#IDSelector1
{
	font-weight:bold;
}

#IDSelector2
{
	text-decoration:underline;
}

.ClassSelector1
{
	color:red;
}

<html>
<head></head>
<body>

	<span id="IDSelector1" class="ClassSelector1">Text Here</span> <!-- This will be bold and red but not underlined -->
	<span id="IDSelector2" class="ClassSelector1">Text Here</span> <!-- This will be underlined and red but not bold -->

</body>
</html>