MFC post方法提交数据提交不过

下面是我的代码请大神帮我看一下  哪里有问题
pHttpConnect = session->GetHttpConnection(_T("202.193.80.58"), nPort); //post方法提交登录数据
    pFile = pHttpConnect->OpenRequest(CHttpConnection::HTTP_VERB_POST, _T("/academic/j_acegi_security_check"));
//下面是post请求头数据 通过火狐浏览器抓包获得
CString head;
pFile->AddRequestHeaders(_T("Host: 202.193.80.58:81"));
pFile->AddRequestHeaders(_T("User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:49.0) Gecko/20100101 Firefox/49.0"));
pFile->AddRequestHeaders(_T("Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8"));
pFile->AddRequestHeaders(_T("Accept-Language: zh-CN,zh;q=0.8,en-US;q=0.5,en;q=0.3"));
pFile->AddRequestHeaders(_T("Accept-Encoding: gzip, deflate"));
pFile->AddRequestHeaders(_T("Referer: http://202.193.80.58:81/academic/index.jsp"));
pFile->AddRequestHeaders(_T("cookie:")+cookie.Left(47));
pFile->AddRequestHeaders(_T("Connection: keep-alive"));
pFile->AddRequestHeaders(_T("Upgrade-Insecure-Requests: 1"));
pFile->AddRequestHeaders(_T(""));

CString pw;
//要提交的数据
pw = _T("j_username=") + name + _T("&j_password=") + password + _T("&j_captcha=") + m_yzm+_T("&button1=%B5%C7+%C2%BC"); //char*request = pw.GetBuffer();               //CString转换为char数组指针
MessageBox(pw.GetBuffer());                        //消息框返回检查要提交的数据
USES_CONVERSION;
//提交数据
pFile->SendRequest(NULL,0, W2A(pw.GetBuffer()), pw.GetLength());