How should this WSDL be used? Php->soapclient

How should this WSDL be used? Tokyu Php-->soapclient
Address: Http://in.commchina.net:8071/service.asmx?WSDL
Find out function: Var_dump ($soap->__getfunctions ());
Get: "Login login (loginwrapper $parameters)"
Query function Parameters: Var_dump ($soap->__gettypes ());
Get: "struct Loginwrapper {string _xml;}"
Specification input XML Description:

the number cannot be empty
The password cannot be empty


Use the following code:
$arr = Array (
' Param ' =>array (
' Number ' = ' 4******* ',
' Pwd ' = ' ******** '
)
);
try{
$wsdl = ' Http://in.commchina.net:8071/service.asmx?WSDL ';
$soap = new SoapClient ($WSDL);
$res = $soap->login (Array (' _xml ' = $arr));
}catch (Exception $e) {
Print_r ($e->getmessage (), true);
}

Error message: The server was unable to process the request. The data at the---> root level is invalid. Line 1, Position 1.


------Solution--------------------
Login Login (Loginwrapper $parameters)

struct Loginwrapper {
String _xml;
}

$param = Array (' _xml ' = '
the number cannot be empty
The password cannot be empty
');

$res = $soap->login (param);
Or
$res = $soap->_call (' Login ', Array ($param));
Or
$res = $soap->_soapcall (' Login ', Array ($param));

