Problem with consuming .NET web service with NuSOAP..

After spending more than two weeks looking for a way to consume a .NET web service with php, i realized that there is no real step by step help for it. But anyway, i got everything working except for one thing. Here's the deal - I'm connecting to a .NET web service at a https wsdl address(belonging to one of my clients). First the web service had no authentication and everything was working fine. Then, after i told them to turn on authentication, they gave me a username and password and the error message that i'll get if authentication fails. I tried every possible way to send that username and password but i still get the error message.. If authentication is turned on, should i be able to view the WSDL at the https address without it asking me for any login details? I'm trying to figure out the problematic area.. here's my code.. $c = new nusoap_client("https://somesite/someService.asmx?WSDL", 'wsdl'); $c->setCredentials('username', password'); $err = $c->getError(); if ($err) { echo '<h2>Constructor error</h2><pre>' . $err . '</pre>'; } $action = "something"; $data = "input data"; $response = $c->call('Account', array("action" => $action, "data" => $data));