<!DOCTYPE html>
<html>
<head>
<style>
.center {
margin: auto;
width: 80%;
border: 3px solid #73AD21;
padding: 10px; # deals with margins within the element itself
margin: 20px; # deals with area around outside of element
}
</style>
</head>
<body>
<h2>Center Align Elements</h2>
<p>To horizontally center a block element (like div), use margin: auto;</p>
<div class="center">
<p><b>Note: </b>Using margin:auto will not work in IE8, unless a !DOCTYPE is declared.</p>
</div>
</body>
</html>