gistfile1.php

// Get the right sort method depending on the cust field type.
		if ($row['field_type'] != 'check')
			$cpf['columns'][$row['col_name']]['sort'] = array(
				'down' => 'LENGTH(t' . $row['col_name'] . '.value) > 0 ASC, IFNULL(t' . $row['col_name'] . '.value, 1=1) DESC, t' . $row['col_name'] . '.value DESC',
				'up' => 'LENGTH(t' . $row['col_name'] . '.value) > 0 DESC, IFNULL(t' . $row['col_name'] . '.value, 1=1) ASC, t' . $row['col_name'] . '.value ASC'
			);

		else
			$cpf['columns'][$row['col_name']]['sort'] = array(
				'down' => 't' . $row['col_name'] . '.value DESC',
				'up' => 't' . $row['col_name'] . '.value ASC'
			);