PHP vTiger6使用vtwsclib创建帐户问题

I am trying to figure out how to programmatically create a "Account" in vTiger6.5 using its Web Services API.

I am currently using the official vtwsclib v1.5 PHP Library. The log in, appears to succeed and I can also successfully perform a doDescribe on the module, however doCreate returns 'false' no matter what I do.

Sample below. Am I missing anything?

$url = 'http://vtiger.mydomain.com/';
$client = new Vtiger_WSClient($url);
$login = $client -> doLogin('systemuser', 'O8nFgnotrealkey');
if (!$login)
    echo 'Login Failed';
else {
    $module = "Accounts";
    $record = $client -> doCreate($module, Array('accountname'=>'S1', 
                           'account_type'=>'Prospect', 'phone'=>'75584'));


    if ($record) {
        $recordid = $client -> getRecordId($record['id']);
    }
}

Returns:

$record: bool(false)

With $client->lastError() i now what my error ,I have create same mandatory fields

 $module = 'Accounts';
 $record = $client->doCreate($module, Array('accountname'=>'c2', 'account_type'=>'Prospect', 'industry'=>'444', 'phone'=>'4555',cf_753=>'Code',cf_755=>'45588','assigned_user_id' => '14x4'));
    if($record) {
        echo "done";
        //$recordid = $client->getRecordId($record['id']);
        //echo "Record ".$recordid;
    } 
    else {
        $wasError= $client->lastError();
        if($wasError) {
            echo "</br>last error : ".$wasError['code'] . ':' . $wasError['message'];
        }

    }