Windows Store Apps and Send Message / SMS (C#)

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using Windows.Devices.Geolocation;
using Windows.Foundation;
using Windows.Foundation.Collections;
using Windows.UI.Core;
using Windows.UI.Xaml;
using Windows.UI.Xaml.Controls;
using Windows.UI.Xaml.Controls.Primitives;
using Windows.UI.Xaml.Data;
using Windows.UI.Xaml.Input;
using Windows.UI.Xaml.Media;
using Windows.UI.Xaml.Navigation;

using Windows.UI.Popups;
using Windows.Devices.Sms; 

// The Blank Page item template is documented at http://go.microsoft.com/fwlink/?LinkId=234238

namespace WindowsStoreApps
{
    /// <summary>
    /// An empty page that can be used on its own or navigated to within a Frame.
    /// </summary>
    /// 
    public sealed partial class MainPage : Page
    {

        private SmsDevice device; 

        public MainPage()
        {
            this.InitializeComponent();
        }

        private async void btnSend_Click(object sender, RoutedEventArgs e)
        {

            try
            {
                device = await SmsDevice.GetDefaultAsync();
                SmsTextMessage msg = new SmsTextMessage();
                msg.To = this.txtTo.Text;
                msg.Body = this.txtMessage.Text;

                await device.SendMessageAsync(msg);

                MessageDialog msgDialog = new MessageDialog("Text message sent", "Status");
                await msgDialog.ShowAsync();
            }
            catch (Exception err)
            {
                device = null;
            } 
        }

    }
}

    // Handle a request to listen for received messages. 
        private async void Receive_Click(object sender, RoutedEventArgs e) 
        { 
            // If this is the first request, get the default SMS device. If this 
            // is the first SMS device access, the user will be prompted to grant 
            // access permission for this application. 
            if (device == null) 
            { 
                try 
                { 
                    rootPage.NotifyUser("Getting default SMS device ...", NotifyType.StatusMessage); 
                    device = await SmsDevice.GetDefaultAsync(); 
                } 
                catch (Exception ex) 
                { 
                    rootPage.NotifyUser("Failed to find SMS device\n" + ex.Message, NotifyType.ErrorMessage); 
                    return; 
                } 
            } 
 
            // Attach a message received handler to the device, if not already listening 
            if (!listening) 
            { 
                try 
                { 
                    msgCount = 0; 
                    device.SmsMessageReceived += device_SmsMessageReceived; 
                    listening = true; 
                    rootPage.NotifyUser("Waiting for message ...", NotifyType.StatusMessage); 
                } 
                catch (Exception ex) 
                { 
                    rootPage.NotifyUser(ex.Message, NotifyType.ErrorMessage); 
 
                    // On failure, release the device. If the user revoked access or the device 
                    // is removed, a new device object must be obtained. 
                    device = null; 
                } 
            } 
        }