From where I can get Microsoft.CRM.Service.Utility dll ?

Hi pals,I'm trying to create a contact record in MSCRM2011 online using an external web page.I couldn't find Microsoft.CRM.Service.Utility dll from sdk. can any body help me.. 

Thanks ...  :)

using System;
using Microsoft.Crm;
using Microsoft.Crm.Tools;
using System.Net;
using Microsoft.Xrm.Sdk;
using Microsoft.Crm.Services.Utility;   // * Did not referenced
using System.ServiceModel.Description;
using Microsoft.Xrm.Sdk.Client;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.Collections.Generic;
using System.Data.SqlClient;
using System.Web.Services;

public partial class crm_contact : System.Web.UI.Page
{

    private static ClientCredentials GetDeviceCredentials()
    {
        return Microsoft.Crm.Services.Utility.DeviceIdManager.LoadOrRegisterDevice();
    }



    protected void Page_Load(object sender, EventArgs e)
    {

    }
    protected void Button1_Click(object sender, EventArgs e)
    {

    



        {
            //Authenticate using credentials of the logged in user;       
            ClientCredentials Credentials = new ClientCredentials();
            //Credentials.Windows.ClientCredential = CredentialCache.DefaultNetworkCredentials;
            Credentials.UserName.UserName = "users.onmicrosoft.com";
            Credentials.UserName.Password = "Pass1";
            //This URL needs to be updated to match the servername and Organization for the environment.
            Uri OrganizationUri = new Uri("https://******.api.crm5.dynamics.com/XRMServices/2011/Organization.svc");
            Uri HomeRealmUri = null;
       
            //OrganizationServiceProxy serviceProxy;       
            using (OrganizationServiceProxy serviceProxy = new OrganizationServiceProxy(OrganizationUri, HomeRealmUri,Credentials,GetDeviceCredentials()))
            {
                serviceProxy.EnableProxyTypes();
                IOrganizationService service = (IOrganizationService)serviceProxy;

                //Instantiate the contact object and populate the attributes.
                Entity contact = new Entity("contact");
                contact["firstname"] = txtFirstName.Text.ToString();
                contact["lastname"] = txtLastName.Text.ToString();
                contact["emailaddress1"] = txtEmailAddress.Text.ToString();
                contact["telephone1"] = txtPhoneNumber.Text.ToString();
                Guid newContactId = service.Create(contact);

                //This code will clear the textboxes after the contact is created.
                txtFirstName.Text = "";
                txtLastName.Text = "";
                txtEmailAddress.Text = "";
                txtPhoneNumber.Text = "";
            }
        } 
    }
}