PHP API ask me to "check credentials"

[由超]

I setup my OM on my Mac. user admin can login successfully. When I use the php 
API, I get error message as:

<h2>Error While signing into OpenMeetings, please check 
credentials</h2><pre>-10</pre>
Failed to login


My OM admin URL is : http://localhost:5080/openmeetings/#user/dashboard


the following is my code. Thanks for any advice.


<pre>

<?php
require_once '../scripts/OmGateway.php';


$gw = new OmGateway(array(
                'protocol' => 'http',
                'host' => 'localhost',
                'port' => '5080',
                'context' => 'openmeetings',
                'user' => 'admin',
                'pass' => 'admin',
                'module' => 'api_test'
));
if ($gw->login()) {
        echo "login successfully";
} else {
        die("\nFailed to login\n");
}
</pre>