Prevent trimming spaces between words in webservices while displaying in browser

using System;
    using System.Collections.Generic;
    using System.Linq;
    using System.Web;
    using System.Web.Services;

    namespace StringTest
    {
       /// <summary>
       /// Summary description for StringTest
       /// </summary>
       [WebService(Namespace = "http://tempuri.org/")]
       [WebServiceBinding(ConformsTo = WsiProfiles.BasicProfile1_1)]
       [System.ComponentModel.ToolboxItem(false)]
       // To allow this Web Service to be called from script, using ASP.NET AJAX, uncomment the following line. 
       // [System.Web.Script.Services.ScriptService]
       public class StringTest : System.Web.Services.WebService
       {

           [WebMethod]

           public string HelloWorld(string str)
           {
               return str;
           }
       }
    }

When I provide the input as "Hello         world", I'm getting the result as Hello world (Nine spaces between the words has been reduced to one).



How can i Prevent trimming spaces between words in webservices?

using System;
    using System.Collections.Generic;
    using System.Linq;
    using System.Web;
    using System.Web.Services;

    namespace StringTest
    {
       /// <summary>
       /// Summary description for StringTest
       /// </summary>
       [WebService(Namespace = "http://tempuri.org/")]
       [WebServiceBinding(ConformsTo = WsiProfiles.BasicProfile1_1)]
       [System.ComponentModel.ToolboxItem(false)]
       // To allow this Web Service to be called from script, using ASP.NET AJAX, uncomment the following line. 
       // [System.Web.Script.Services.ScriptService]
       public class StringTest : System.Web.Services.WebService
       {

           [WebMethod]

           public string HelloWorld(string str)
           {
               return str;
           }
       }
    }