How to add parameters in android http POST?

How to make an http POST and adding parameters.

how to add parameters? you must have something like.

// Add your data  
List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>(2);  
nameValuePairs.add(new BasicNameValuePair("userid", "12312"));  
nameValuePairs.add(new BasicNameValuePair("sessionid", "234"));  
httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));  

This is a complete method:

public void postData() {
    // Create a new HttpClient and Post Header
    HttpClient httpclient = new DefaultHttpClient();
    HttpPost httppost = new HttpPost("http://www.yoursite.com/myexample.php");

try {
    // Add your data
    List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>(2);
    nameValuePairs.add(new BasicNameValuePair("id", "12345"));
    nameValuePairs.add(new BasicNameValuePair("stringdata", "stackoverflow.com is Cool!"));
    httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));

    // Execute HTTP Post Request
    HttpResponse response = httpclient.execute(httppost);
    
   } catch (ClientProtocolException e) {
      // TODO Auto-generated catch block
   } catch (IOException e) {
      // TODO Auto-generated catch block
   }
}