anchor.diff:      }
       String htmlFragment = "";
       if(word != null && !"".equals(word.trim())){
  -        List<String> words = (List<String>)application.getAttribute("words_string");
  +        String words_type = request.getParameter("words_type");
  +        if(words_type == null){
  +            words_type = "all";
  +        }
  +        request.setAttribute("words_type", words_type.trim());
  +        String key = "words_string_"+words_type;
  +        List<String> words = (List<String>)session.getAttribute(key);
           if(words == null){
               words = new ArrayList<String>();
  -            for(Word item : WordSources.getSyllabusVocabulary()){
  -                words.add(item.getWord());
  +            if("ALL".equals(words_type.trim())){
  +                for(Word item : WordSources.getAll()){
  +                    words.add(item.getWord());
  +                }
  +            }else if("SYLLABUS".equals(words_type.trim())){
  +                for(Word item : WordSources.getSyllabusVocabulary()){
  +                    words.add(item.getWord());
  +                }
  +            }else{
  +                String resource = "/word_"+words_type+".txt";
  +                for(Word item : WordSources.get(resource)){
  +                    words.add(item.getWord());
  +                }
               }
  -            application.setAttribute("words_string", words);
  +            session.setAttribute(key, words);
           }
           SimilarWord similarWord = new SimilarWord();
           Hits result = similarWord.compute(word, new EditDistanceTextSimilarity(), words, count);
  
positive.code:         <font color="red">输入单词：</font><input id="word" name="word" value="<%=word==null?"":word%>" size="50" maxlength="50"><br/>
          <font color="red">结果数目：</font><input id="count" name="count" value="<%=count%>" size="50" maxlength="50"><br/>
          <font color="red">选择词典：</font>
          <jsp:include page="dictionary-select.jsp"/>
      </p>
      <p></p>
      <p><a href="#" onclick="submit();">提交</a></p>
  
negative.code:             var word = document.getElementById("word").value;
              var count = document.getElementById("count").value;
              var dict = document.getElementById("dict").value;
              var words_type = document.getElementById("words_type").value;
              if(word == ""){
                  return;
              }
              location.href = "similar-word.jsp?word="+word+"&count="+count+"&dict="+dict+"&words_type="+words_type;
          }
      </script>
  </head>
  