 <p>Perhaps it's <code>$n_part = $_COOKIE['crea_camp']['n_part'];</code>.</p> <p>You may use <code>print_r()</code> or <code>var_dump()</code> to see the contents of a variable, for instance <code>print_r($_COOKIE);</code> and check what the key names are.</p> <p>You can as well always check what cookies are set/sent back in/from the browser using the respective developer tools (Firebug, Firefox Dev Tools, Chrome Dev Tools, etc.).</p>