delphi中调用webservice时，出错，请大虾帮忙~~~

--这是我写的函数
function Tfrm_login.InitADAuth: string;
var
  furls: string;
  Iservice : ADAuthSoap;
begin
  //取WS地址
  QueryOpen(tempquery1,'select top 1 * from pln_message where class_id = ''ADAuth'' and remark = ''ccc'' ');
  if not tempquery1.Isempty then
  begin
  //验证
  Iservice := GetADAuthSoap(true,'http://svn.ccin.com/MOAWebService/ADAuth.asmx?WSDL');
  result := Iservice.ADAuthByFlag(UserName,password,tempquery1.Fieldbyname('mes_name').asstring);
  end
  else
  begin
  result := 'false';
  Iservice.free;
  end;
end;

调用如下webservice

// ************************************************************************ //
// The types declared in this file were generated from data read from the
// WSDL File described below:
// WSDL : http://svn.ccin.com/MOAWebService/ADAuth.asmx?wsdl
// Encoding : utf-8
// Version : 1.0
// (2011-9-4 13:43:12 - $Revision: 1.9.1.0.1.0.1.9 $)
// ************************************************************************ //

unit ADAuth;

interface

uses InvokeRegistry, Types, XSBuiltIns;

type

  // ************************************************************************ //
  // The following types, referred to in the WSDL document are not being represented
  // in this file. They are either aliases[@] of other types represented or were referred
  // to but never[!] declared in the document. The types from the latter category
  // typically map to predefined/known XML or Borland types; however, they could also 
  // indicate incorrect WSDL documents that failed to declare or import a schema type.
  // ************************************************************************ //
  // !:string - "http://www.w3.org/2001/XMLSchema"


  // ************************************************************************ //
  // Namespace : http://tempuri.org/
  // soapAction: http://tempuri.org/%operationName%
  // transport : http://schemas.xmlsoap.org/soap/http
  // binding : ADAuthSoap
  // service : ADAuth
  // port : ADAuthSoap
  // URL : http://svn.ccin.com/MOAWebService/ADAuth.asmx
  // ************************************************************************ //
  ADAuthSoap = interface(IInvokable)
  ['{56D59372-0D3E-E8B9-1A41-10407C99CD92}']
  function IsAuthPass(const strUserName: String; const strPassword: String): String; stdcall;
  function ADAuthByFlag(const name: String; const pwd: String; const flag: String): String; stdcall;
  end;

function GetADAuthSoap(UseWSDL: Boolean=System.False; Addr: string=''): ADAuthSoap;


implementation
  uses SOAPHTTPClient;

function GetADAuthSoap(UseWSDL: Boolean; Addr: string): ADAuthSoap;
const
  defWSDL = 'http://svn.ccin.com/MOAWebService/ADAuth.asmx?wsdl';
  defURL = 'http://svn.ccin.com/MOAWebService/ADAuth.asmx';
  defSvc = 'ADAuth';
  defPrt = 'ADAuthSoap';
var
  RIO: THTTPRIO;
begin
  Result := nil;
  if (Addr = '') then
  begin
  if UseWSDL then
  Addr := defWSDL
  else
  Addr := defURL;
  end;
  RIO := THTTPRIO.Create(nil);
  try
  if UseWSDL then
  begin
  RIO.WSDLLocation := Addr;
  RIO.Service := defSvc;
  RIO.Port := defPrt;
  end else
  RIO.URL := Addr;
  Result := (RIO as ADAuthSoap);
  finally
  if Result = nil then
  RIO.Free;
  end;
end;


initialization
  InvRegistry.RegisterInterface(TypeInfo(ADAuthSoap), 'http://tempuri.org/', 'utf-8');
  InvRegistry.RegisterDefaultSOAPAction(TypeInfo(ADAuthSoap), 'http://tempuri.org/%operationName%');
  InvRegistry.RegisterInvokeOptions(TypeInfo(ADAuthSoap), ioDocument);

end.



出现奇怪的问题，按F9进行代码跟踪时，可以从服务器取数据，但直接运行exe文件时，报地址错误
---------------------------
[DEBUG]
---------------------------
Access violation at address 07992334. Write of address 07992334
---------------------------
确定  
---------------------------


这是怎么回事啊~~

至少这句：

Iservice.free;

是没用的，可以注释掉

嗯，我在胡乱试，有点抓狂

谁帮忙提点意见，不是delphi环境有问题

谁帮我下啊，一天都在搞这两句代码，崩溃啊，我可以加分的，一句话