Android app call to .NET web service -

i have created .net web service , trying fetch data using xmlpullparser android app getting http/1.1 500 internal server error

this sample httprequest:

post /companyservice.asmx/adduser http/1.1 host: 192.168.141.1 content-type: application/x-www-form-urlencoded content-length: length  username=string&password=string&phonenumber=string&emailid=string&position=string&address=string 

and android code is:

 httppost httppost = new httppost("http://192.168.141.1/companyservice.asmx/adduser");              try {                 // add data                 list<namevaluepair> namevaluepairs = new arraylist<namevaluepair>(6);                 namevaluepairs.add(new basicnamevaluepair("username", "aaa"));                 namevaluepairs.add(new basicnamevaluepair("password", "a"));                 namevaluepairs.add(new basicnamevaluepair("phonenumber", "a"));                 namevaluepairs.add(new basicnamevaluepair("emailid", "a"));                 namevaluepairs.add(new basicnamevaluepair("position", "a"));                 namevaluepairs.add(new basicnamevaluepair("address", "a"));                 httppost.setentity(new urlencodedformentity(namevaluepairs));                  // execute http post request                 httpresponse response = httpclient.execute(httppost);             } catch (clientprotocolexception e) {                 e.printstacktrace();              } catch (ioexception e) {               e.printstacktrace();             } 

what doing wrong here?

edit: log file contains:

2014-03-06 07:24:19 192.168.141.1 post /companyservice.asmx/adduser - 80 - 192.168.141.101 apache-httpclient/unavailable+(java+1.4) - 500 0 0 10 

i found solution. had not added protocols in web.config. here code

  <webservices>     <protocols>         <add name="httpget"/>         <add name="httppost"/>     </protocols>    </webservices>