public static function json_error($msg = '')
{
$params = json_encode(Input::all());
$str = $msg . ' ' . $params;
Requests::log($str);
$err = new stdClass();
$err->status = 'error';
$err->message = trim($msg);
if (isset($_GET['jsoncallback'])) {
header('Content-Type:text/html;Charset=utf-8');
echo $_GET['jsoncallback'] . "(" . json_encode($err) . ")";
exit;
} else {
header('Content-Type: application/json');
$retval = json_encode($err);
echo $retval;
exit;
}
}