C / C++ / MFC

void LOGINTOWEB(void *Params)
{
	CMFToolbar *m_pToolbar=(CMFToolbar*)Params;
	try
	{
		CSingleLock m_lock(&(m_pToolbar->m_sema));  
		m_lock.Lock();
		m_pToolbar->LoginToWeb1(m_pToolbar->m_strqpWebUser,m_pToolbar->m_strqpWebPass,m_pToolbar->m_strqpWebOrg,m_pToolbar->m_strqpWebUrl);      
		m_lock.Unlock();
		_endthread(); 
	}
	catch(...)
	{
	}
}

bool CMFToolbar::LoginToWeb1(CString UserName,CString Password,CString Organization,CString Url)
{
	bool bFlg=false;
	try
	{
		CString params;
                /* Here the exception is generated when called from the  thread. When this function called without any thread it will run.Why it fails in thread?????*/
		MSXML::IXMLHttpRequestPtr httpReq(__uuidof(XMLHTTPRequest));

		_bstr_t  HTTPMethod ;
		_variant_t noAsync = _variant_t( (bool)false );
		_variant_t user=_variant_t((CString)UserName);
		_variant_t pass=_variant_t((CString)Password);

		CString strUrl=Url;
		strUrl+=QPWEB_SUFFIX;
		
		//MessageBox(strUrl);
		_bstr_t url(strUrl.GetBuffer(strUrl.GetLength())); 

		HTTPMethod = _bstr_t("GET");
		httpReq->open(HTTPMethod,url,noAsync,vtMissing,vtMissing);
		httpReq->setRequestHeader("Content-Type", "application/x-www-form-urlencoded");
		httpReq->setRequestHeader("Content-Length","0");
		
		params.Empty(); 
		params="UserName=";
		params+=UserName;
		params+="&Password=";
		params+=Password;
		params+="&Organization=";
		params+=Organization;

		//MessageBox(params);

		VARIANT vRequest;
		vRequest.vt = VT_BSTR;
		vRequest.bstrVal = params.AllocSysString();

		httpReq->send(vRequest);
		BSTR strText;
		int nPos1,nPos2;
		CString strsession,szResult1,szResult;

		_bstr_t bsResponse = httpReq->responseText;

		CString response((LPCWSTR)bsResponse);
		MessageBox(response);

		nPos1=response.Find("<SessionId>");
		nPos2=response.Find("</SessionId>"); 
		nPos1+=11;
		strsession=response.Mid(nPos1,(nPos2-nPos1)); 
		m_qpWebSessionId=strsession;
		//MessageBox(m_qpWebSessionId); 

		nPos1=response.Find("<LoginToqpWebResult>");
		nPos2=response.Find("</LoginToqpWebResult>"); 
		nPos1+=20;
		
		szResult1=response.Mid(nPos1,(nPos2-nPos1)); 
		
		/*nPos1=szResult1.Find("<LoginToqpWebResult>"); 
		nPos2=szResult1.GetLength();
		nPos1+=20;
		
		szResult=szResult1.Mid(nPos1,(nPos2-nPos1)); */
		szResult=szResult1;
		szResult.MakeLower(); 
		//MessageBox(szResult);

		if(szResult=="true")
		{
			bFlg=true;
		}
		else
			MessageBox("Invalid account information.Please check your login details",_T("qpToolbar"),MB_ICONEXCLAMATION);
	}
	catch(...)
	{
		MessageBox("Login webservice not recheable");
	}
	return bFlg;
}