Sequential dialing with Twilio

script.php

$arr = array('416...','647...','905..');

if (isset($_REQUEST['index'])) {
    $index = $_REQUEST['index'];
} else {
    $index = 0;
}

$next = $index + 1;

$call = $client->account->calls->create(
    $from,
    $arr[$index],
    'http://path/to/your/script?index=' . $next,
    array('Timeout' => 1)
);