Android KSoap Output Error

[rockenpeace]

I've tried to work web service on android but I've taken an error in emulator output:

org.xmlpull.v1.XmlPullParserException:expecteed: START_TAG {http://schemas.xmlsoap.org/soap/envelope/}Envelope(position:START_TAG@1:6 in java.io.InputStreamReader@43e567a0)

In here, my code:

package com.webServiceDeneme;
import org.ksoap2.SoapEnvelope;
import org.ksoap2.serialization.PropertyInfo;
import org.ksoap2.serialization.SoapObject;
import org.ksoap2.serialization.SoapPrimitive;
import org.ksoap2.serialization.SoapSerializationEnvelope;
import org.ksoap2.transport.AndroidHttpTransport;
import android.app.Activity;import android.os.Bundle;
import android.view.View;import android.view.View.OnClickListener;
import android.widget.*; 

public class WebServiceDenemeActivity extends Activity {
  Button btn;
  @Overridepublic void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);
    btn=(Button)findViewById(R.id.button1);
    btn.setOnClickListener(new OnClickListener() {
        @Override        public void onClick(View v) {
            // TODO Auto-generated method stub
            String NAMESPACE="http://www.vakifbank.com.tr/";
            String METHOD_NAME="faiz-maliyet-oranlari.aspx";
            String SOAP_ACTION="http://www.vakifbank.com.tr/faiz-maliyet-oranlari.aspx";
            String URL="http://192.168.2.1/VipEvents/Services/BasicServices.asmx";
            SoapObject request=new SoapObject(NAMESPACE, METHOD_NAME);
            SoapSerializationEnvelope envelope=new SoapSerializationEnvelope(SoapEnvelope.VER11);
            envelope.dotNet=true;
            envelope.setOutputSoapObject(request);
            try            {
                AndroidHttpTransport aht=new AndroidHttpTransport(URL);
                aht.call(SOAP_ACTION, envelope);
                SoapPrimitive res=(SoapPrimitive)envelope.getResponse();
                btn.setText(res.toString());
            }
            catch (Exception e) {
                // TODO: handle exception
                btn.setText(e.toString());
                e.printStackTrace();
            }
        }
    });
  }
}

any help,please..
regards..