soap - PHP Server was unable to process request -

this coding can 1 help:

<?php  class clswsseauth {            private $username;            private $password;     private $meruser;            private $merpass;         function __construct($username, $password) {                   $this->username=$username;                   $this->password=$password;      //$this->merhcantusername=$meruser;                   //$this->merhcantpassword=$merpass;                }  }   /*class clswssetoken {          private $usernametoken;          function __construct ($innerval){              $this->usernametoken = $innerval;          }  }*/  ?>   <!--step2: create soap variables username , password -->  <?php include("lib/nusoap.php"); $username = $_request['usname']; $password = $_request['uspass']; $meruser = $_request['merusname']; $merpass = $_request['meruspass'];  //check provider security name-space using.  $strwssens = "http://localhost/royal_new/";    $objsoapvaruser = new soapvar($username, xsd_string, null, $strwssens, null, $strwssens);  $objsoapvarpass = new soapvar($password, xsd_string, null, $strwssens, null, $strwssens);  $objsoapvarmeruser = new soapvar($meruser, xsd_string, null, $strwssens, null, $strwssens);  $objsoapvarmerpass = new soapvar($merpass, xsd_string, null, $strwssens, null, $strwssens);    ?>   <!--step3: create object auth class , pass in soap var -->  <?php  $objwsseauth = new clswsseauth($objsoapvaruser, $objsoapvarpass);   ?>   <!--step4: create soapvar out of object of auth class-->   <?php  $objsoapvarwsseauth = new soapvar($objwsseauth, soap_enc_object, null, $strwssens, 'usernametoken', $strwssens);   ?>   <!--step5: create object token class-->   <?php  //$objwssetoken = new clswssetoken($objsoapvarwsseauth); ?>   <!--step6: create soapvar out of object of token class-->   <?php  //$objsoapvarwssetoken = new soapvar($objwssetoken, soap_enc_object, null, $strwssens, 'usernametoken', $strwssens);  ?>   <!--step7: create soapvar 'security' node-->   <?php  //$objsoapvarheaderval=new soapvar($objsoapvarwssetoken, soap_enc_object, null, $strwssens, 'security', $strwssens); ?>   <!--step8: create header object out of security soapvar-->   <?php  //$objsoapvarwsseheader = new soapheader($strwssens, 'security', $objsoapvarheaderval,true, 'http://services.l2payments.com/merchantservices.asmx?wsdl');   //third parameter here makes 'mustunderstand=1  //forth parameter generates 'actor="http://abce.com"'  ?>   <!--step9: create object of soap client-->   <?php  $param = array('merhcantusername' => $username,'merhcantpassword' =>$password); $objclient = new soapclient('http://services.l2payments.com/merchantservices.asmx?wsdl', $param); ?>   <!--step10: set headers soapclient object -->  <?php  //$objclient->__setsoapheaders(array($objsoapvarwsseheader)); ?>   <!--step 11: final call method -->  <?php try {     $objresponse = $objclient->__soapcall('loginrequest', $param);  // note: same results without or without exceptions => true } catch(exception $e) {     var_dump($e); }  ?> 

i getting error:

object(soapfault)#9 (9) {  ["message:protected"]=>  string(96) "server unable process request. ---> object reference not set instance of object."  ["string:private"]=>  string(0) ""  ["code:protected"]=>  int(0)  ["file:protected"]=>  string(32) "c:\wamp\www\royal_new\server.php"  ["line:protected"]=>  int(102)  ["trace:private"]=>  array(1) {   [0]=>  array(6) {    ["file"]=>  string(32) "c:\wamp\www\royal_new\server.php"    ["line"]=>  int(102)    ["function"]=>  string(10) "__soapcall"    ["class"]=>  string(10) "soapclient"    ["type"]=>  string(2) "->"    ["args"]=>  array(2) {     [0]=>  string(12) "loginrequest"     [1]=>  array(2) {      ["merhcantusername"]=>  string(5) "manoj"      ["merhcantpassword"]=>  string(5) "manoj" } } } }      ["faultstring"]=>  string(96) "server unable process request. ---> object reference not set instance of object."  ["faultcode"]=>  string(11) "soap:server"  ["detail"]=>  string(0) "" }