PHP to Web Service array param problem

Hi everybody,
If I am calling a C# web service from PHP and sending an array like this:
$param=array('cin'=>'00000','password'=>'00000');
How would the web method look like? or what would be the type that is expecting? because I have something like this:
[WebMethod]
public string Login (string CIN, string Password)???

{}

and this is some sample from the request and the response:

- <ns2407:Login xmlns:ns2407="Array">


  <cin xsi:type Go to the complete details ...