ช่วยหน่อยนะค่ะ จะเริ่มทำ web service ด้วย PHP แต่ไม่มีความรู้เลยด้านนี้ค่ะ

require_once("nusoap.php");
//---Instance Class---//
$server = new soap_server();
$server->configureWSDL('soap', "urn:echoStringwsdl");
$server->wsdl->addComplexType( 
   	'DataList', 
        'complexType', 
        'struct', 
        'all', 
        '', 
       array( 
            'good_id' => array('name' => 'good_id', 'type' => 'xsd:string'), 
            'name'  => array('name' => 'name', 'type'  => 'xsd:string'),
	    'detail'  => array('name' => 'detail', 'type'  => 'xsd:string'),
	    'picture'  => array('name' => 'picture', 'type'  => 'xsd:string')
       ) 
); 

$server->wsdl->addComplexType( 
    'DataListRs', 
    'complexType', 
    'array', 
    '', 
    'SOAP-ENC:Array', 
    array(), 
    array( 
        array('ref'=>'SOAP-ENC:arrayType','wsdl:arrayType'=>'tns:DataList[]') 
    ), 
    'tns:DataList' 
); 

$server->register('echoString',           // method name 
    array('inputString' => 'xsd:string'), // input parameters 
    array('return' => 'tns:DataListRs'),  // output parameters 
    'urn:echoStringwsdl',                 // namespace 
    'urn:echoStringwsdl#echoString',      // soapaction 
    'rpc',                 				  // style 
    'encoded',             				  // use 
    'Return a list of data'        		  // documentation 
); 

function echoString($inputString) { 
	//---Connect DB---//
	$host="localhost";
	$username="root";
	$passwd="";
	$dbname="test";
	$conn = mysql_pconnect($host,$username,$passwd)or die("Can't connect to Server");
	mysql_select_db($dbname)or die("Can't connect to Database");

	$result = mysql_query("SELECT *  FROM good WHERE name like '%".$inputString."%'"); 
	$response = array(); 

	while ($row = mysql_fetch_assoc($result)) { 
		array_push($response, $row); 
	} 
	
	return $response;    
} 

// Use the request to invoke the service 
$HTTP_RAW_POST_DATA = isset($GLOBALS['HTTP_RAW_POST_DATA']) ? $GLOBALS['HTTP_RAW_POST_DATA'] : ''; 
$server->service($HTTP_RAW_POST_DATA); 

<?php
//---เีรียกใช้ library nusoap---//
require_once('nusoap.php');
//---สร้าง Instance Class---//
$client = new nusoap_client('http://localhost/webservice/ns_server.php', true);
//---เรียกใช้ ฟังข์ชั่น webservice---//
$result = $client->call('echoString', array('inputString' => "a"));
print_r($result);
if ($client->fault) {
	echo '<h2>Fault</h2><pre>'; print_r($result); echo '</pre>';
} 
$err = $client->getError();
if ($err) {
	echo '<h2>Constructor error</h2><pre>' . $err . '</pre>';
}
?>