Sending WSDL file via SOAP

Hi,

Im trying to send a WSDL file to another server.
I have no idea how to do this also this is my first time to work with API(SOAP).

I found a many tutorial about this and they are not working in my application.
The last tutorial is from this website (http://phpsblog.agustinvillalba.com/crea...deigniter/).

I follow everything in this tutorial exactly.

But the problem is with

PHP Code:

$this->nusoap_server = new soap_server(); 


The Error is

Code:

Fatal error: Class 'soap_server' not found in D:\xampp\htdocs\interface\application\controllers\interface\NuSoapServer.php on line 7

And in the box with red border line

Code:

A PHP Error was encountered
Severity: Error
Message: Class 'soap_server' not found
Filename: interface/NuSoapServer.php
Line Number: 7
Backtrace:

Why im getting error about new soap_server?

Thanks