i.e.

<?php
class SoapController
{
 function HelloWorld($name)
 {
  return "Hello ". strrev($name) ;
 }
}
ini_set("soap.wsdl_cache_enabled", "0");
$server = new SoapServer('http://example.com/soap.wsdl');
$server->setClass("SoapController");
$server->handle();
?>

and

<?php
ini_set("soap.wsdl_cache_enabled", "0");
$client = new SoapClient('http://example.com/soap.wsdl', array('trace' => 1));
print_r($client->HelloWorld("Damian"));
?>