SimpleMachines / SMF2.1

			$_REQUEST['start'] = (int) $_REQUEST['start'];

		}

		// ... or a specific message ...

		elseif (strpos($_REQUEST['start'], 'msg') === 0)

		{

			$virtual_msg = (int) substr($_REQUEST['start'], 3);

			$_REQUEST['start'] = $virtual_msg === 0 ? 0 : 'msg' . $virtual_msg;

		}

		// ... or whatever is new ...

		elseif (strpos($_REQUEST['start'], 'new') === 0)

		{

			$_REQUEST['start'] = 'new';

		}

		// ... or since a certain time ...

		elseif (strpos($_REQUEST['start'], 'from') === 0)

		{

			$timestamp = (int) substr($_REQUEST['start'], 4);

			$_REQUEST['start'] = $timestamp === 0 ? 0 : 'from' . $timestamp;

		}

		// ... or something invalid, in which case we reset it to 0.

		else

			$_REQUEST['start'] = 0;