PHP SOAP如何传入复杂对象

在php SOAP中使用数组来传入复杂参数，代码例如下：

	$soapClient = new SoapClient('https://www.paymentexpress.com/WSTest/PXWS.asmx?WSDL');
	$transactionDetails = array(
		'acmout'=>'12.35',
		'cardNumber'=>'',
		'dateExpiry'=>'1010',
		'txnDescription'=>'Payment Test',
		'txnRef'=>'PT937459',
		'currency'=>'USD',
	);
	$param=array(
		'postUsername'       => 'My_Dev',
		'postPassword'       => 'My_Password',
		'transactionDetails' => $transactionDetails,
	);
	$ret  = $soapClient->Check3dsEnrollment($param);
	print_r($ret);