ATL Web Sevice Consuming Error

I created a simple ATL Web Service that accepts a string and returns the string reversed.
The code is a shown below:
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// ReverseString.h : Defines the ATL Server request handler class
//
#pragma once

namespace ReverseStringService
{
// all struct, enum, and typedefs for your webservice should go inside the namespace

// IReverseStringService - web service interface declaration
//
[
      uuid("8B57749E-80D9-4A18-96E4-F39E0DBEE610"),
      object
]
__interface IReverseStringService
{
      [id(1)] HRESULT ReverseString([in] BSTR bstrInput, [out, retval] BSTR *bstrOutput);
};


// ReverseStringService - web service implementation
//
[
      request_handler(name="Default", sdl="GenReverseStringWSDL"),
      soap_handler(
            name="ReverseStringService",
            namespace="urn:ReverseStringService",
            protocol="soap"
      )
]
class CReverseStringService :
      public IReverseStringService
{
public:
      // This is a sample web service method that shows how to use the
      // soap_method attribute to expose a method as a web method
      [ soap_method ]
      HRESULT ReverseString(/*[in]*/ BSTR bstrInput, /*[out, retval]*/ BSTR *bstrOutput)
      {
            // Check the outgoing pointer...
            if ( bstrOutput == NULL ) return E_POINTER;

            // Reverse the characters
            *bstrOutput = SysAllocString(_wcsrev(bstrInput));
            


            return S_OK;
      }
      // TODO: Add additional web service methods here
}; // class CReverseStringService

} // namespace ReverseStringService

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The code that consumes the Web services is in C# is as follows:

--------------------------------------------------------------------------------------------------------------------
using System;
using ReverseStringClient.localhost;

namespace ReverseStringClient
{
      /// <summary>
      /// Summary description for Class1.
      /// </summary>
      class Class1
      {
            static void Main(string[] args)
            {
                  // Create an instance of the ATL Server's
                  // Web Service proxy
                  ReverseStringService ws = new ReverseStringService();
                  string strResult = ws.ReverseString("This is a test!");
                  Console.WriteLine("The resulting string was '{0}'",strResult);
            }
      }
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The Web Reference is set to http://localhost/ReverseString/ReverseString.dll?Handler=GenReverseStringWSDL
I am running the Web Service in IIS 5.0 on Win2k Advanced Server.
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When I try and consume the web service I am getting the error below:
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"An unhandled exception of type 'System.Net.WebException' occurred in system.web.services.dll "Additional information: The request failed with HTTP status 405: Method not allowed."
----------------------------------------------------------------------------

I know that HTTP status 405: Method Not Allowed error is raised when the method specified in the Request-Line is not allowed for the resource identified by the Request-URI. I have checked all my settings on IIS they seem to be correct. I don't how to progress further.Could anyone please help