SOAP: Giving Paramters to ASP WebService

Hello,
 
I have a problem with an asp Webservice. I am using soap.connect() method. Like this:
 
var cURL1 = "http://sql/backend-webservice/datei.asmx?wsdl";
var datei_service = SOAP.connect(cURL1);
var succ = datei_service.SetTrimbox("test",1,2);
 
--> succ = false
 
Webservice-Method 'SetTrimbox' does not get any paramters ("test",1,2) from my script. This method should finally write the parameters back to a database. A string and two integers.
 
Do i have to use the request object? Could someone please post a quick example.
 
The Webservice does offer return values - e.g. a simple 'getString' webservice method without any input parameters to it does work.
  
Thank you very much,
Michael