I try to use list_participants api (called on phpfox). Here is the code:

// $surveys = $myJSONRPCClient->list_surveys( $sessionKey );
// foreach($surveys as $survey) {
// echo $survey.'<br/>';
// $participants = $myJSONRPCClient->list_participants( $sessionKey, $survey, 0, 10, true, false );
// foreach($participants as $participant) {
// echo $participant.'<br/>';
// }
// }

i can list surveys by sid
i can print result of $participants with "print_r($participants , null );"
but "echo $participant.'<br/>';" give me no result (blank lines).

What's wrong ??
Please give me a step by step
thanks