How To get all the users From sharepoint groups in client object model

In the below example i have retrieved all the sharepoint users and populated it in a combobox.

Silverlight  Main Page  Program
 

using System;
using System.Collections.Generic;
using System.Linq;
using System.Net;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Animation;
using System.Windows.Shapes;
using Microsoft.SharePoint.Client;
using Microsoft.SharePoint;

namespace users
{

public partial class MainPage : UserControl
{
string user;
GroupCollection Groupcoll;
ClientContext site;
public  MainPage()
{

InitializeComponent();
site = new ClientContext(ApplicationContext.Current.Url);

site.Load(site.Web);
Groupcoll= site.Web.SiteGroups;
site.Load(Groupcoll, groups => groups.Include(group => group.Users));

site.ExecuteQueryAsync(new ClientRequestSucceededEventHandler(OnRequestSucceeded), null);

}

private void OnRequestSucceeded(Object sender, ClientRequestSucceededEventArgs args)
{// This is not called on the UI thread.

Dispatcher.BeginInvoke(datacon);
}

private void datacon()
{
foreach (Group Grp in Groupcoll)
{
UserCollection collUser = Grp.Users;
foreach (User Usr in collUser)
{
user = Convert.ToString(Usr.Title);
combobox1.Items.Add(user);
}
}
}

OUTPUT

}
}