SOAP XML Error method '' not defined in service ''

follow these instructions, it will show you how to install nusoap

How To Install Nusoap.php Class

i need some help with nusoap ,,,I have the following code but when I hit the page, I get the xml error of method '' not defined in service. I don't have a wsdl or anything defined. Is there more I need to do to get the SOAP service set up?


Thanks!

include("nusoap/nusoap.php");

$server=new soap_server();
$server-register('getColumns');

function getColumns(){

$search= new carSearch();

return $search-getSearchColumns();

}
$server-service($HTTP_RAW_POST_DATA);