问题：使用以下代码发送http请求test.php的时候，返回的结果总是跟第一次的一样。
test.php的源码：
//输出1到100的随机数

<?php
echo rand(1,100);
?>

C++源码：

char* server="127.0.0.1";
        char * action="/test.php";
        INTERNET_PORT port = 80;
        char * szHeader= "Accept: */*\r\n"
                  "Accept-Language: zh-cn\r\n"
                  "User-Agent: Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.0; .NET CLR 2.0.50727; .NET CLR 1.1.4322)\r\n"
                  "Host: %s\r\n"
                  "Connection: Closed\r\n\r\n";
        CString szHeaders;
        szHeaders.Format (szHeader,server);
        CInternetSession session;
        CHttpConnection* pConnection = session.GetHttpConnection(server,port);
        CHttpFile* pFile = pConnection->OpenRequest(CHttpConnection::HTTP_VERB_GET,action);//
        BOOL result = pFile->SendRequest(szHeaders,NULL,NULL);
        szHeaders.ReleaseBuffer ();

        CString header;//获取header
        pFile->QueryInfo(HTTP_QUERY_RAW_HEADERS_CRLF,header,0);
        CString data("");//获取HTML
        char szBuff[1025];
        while(1)
        {
                int nReadLength = pFile->Read(szBuff, 1024);
                if(nReadLength==0) break;
                szBuff[nReadLength]='\0';
                data=data+szBuff;
        }
        AfxMessageBox(data);
        pConnection->Close();
        session.Close();
        pFile->Close();
        delete pFile;
        delete pConnection;
        data.ReleaseBuffer ();
        header.ReleaseBuffer ();
        return "";