web services - call webservices by url to android application -

i used soap object achieve task previous answers. unfortunately ,code did not work. gives message "unfortunately,ksoap2sample has stoped". can't found error occurs. when debug code, shows noclassdeffounderror.please me correct code.

this code

package projects.ksoap2sample;  import java.io.ioexception; import android.os.build; import android.os.bundle; import android.os.strictmode; import android.annotation.targetapi; import android.app.activity; import android.view.menu; import android.view.view; import android.view.view.onclicklistener; import android.widget.button; import android.widget.textview; import android.widget.toast;  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.httptransport; import org.ksoap2.transport.httptransportse; import org.xmlpull.v1.xmlpullparserexception;  @targetapi(build.version_codes.gingerbread) public class mainactivity extends activity {  private static final string soap_action = "http://tempuri.org/gettown"; private static final string method_name = "gettown"; private static final string namespace = "http://tempuri.org/"; private static final string url = "http://10.0.2.2/testproject/service.asmx";  private textview lblresult;  @override public void oncreate(bundle savedinstancestate) {     super.oncreate(savedinstancestate);     setcontentview(r.layout.activity_main);      lblresult = (textview) findviewbyid(r.id.textview1);      soapobject request = new soapobject(namespace, method_name);     request.addproperty("id", "dsgfdg");      soapserializationenvelope envelope = new soapserializationenvelope(             soapenvelope.ver11);     envelope.setoutputsoapobject(request);     httptransportse androidhttptransport = new httptransportse(url);     try {         androidhttptransport.call(soap_action, envelope);          // soapprimitive resultsrequestsoap = (soapprimitive)         // envelope.getresponse();         // soapprimitive resultsrequestsoap = (soapprimitive)         // envelope.getresponse();         soapobject resultsrequestsoap = (soapobject) envelope.bodyin;          lblresult.settext(resultsrequestsoap.tostring());         system.out.println("response::" + resultsrequestsoap.tostring());      } catch (exception e) {          system.out.println("error" + e);     }  }  @override public boolean oncreateoptionsmenu(menu menu) {     // inflate menu; adds items action bar if present.     getmenuinflater().inflate(r.menu.main, menu);     return true; } 

this web method asp.net c#

[webmethod] public datatable gettown(string id) {     datatable dt = new datatable();     string strsql = "select personname,gender,civilstatus personaldata personname=" + id;     dt = com.getdatatablefromsql(strsql);     return dt;  }