public String DelQuestion(){
	String sid=request.getParameter("sid");
	String qid=request.getParameter("qid");
	QuestionDAO dao=DAOFactory.getQuestionDAO();
	boolean ret=dao.delQuestion(Long.valueOf(qid));
	if(ret==true){
//		response.sendRedirect("../admin/QuestionAdmin.jsp?sid="+sid);
		return "success";
	}else{
//		response.sendRedirect("../admin/OpResult.jsp?op=Question&ret=false");
		return "fail";
	}
}