PHP 5.3 and '::'
<p>I started into PHP with 5.3 and am using the '::' to access constants ex; class::const. However, when I try to use my code in an older PHP namely 5.1.6 and 5.2.12, I get an error that the '::' is unexpected.</p>

<p>How do I access constants in these older versions of PHP5?</p>
