工作中所写的功能

document.cookie = "key=1";

document.cookie = "name=zhangsan";

cookie中存值形式：key=1,name=zhangsan等

 window.onbeforeunload = function () {
//                // 刷新、关闭 页面之前，清理cookie中的key值。
//               // alert(document.cookie);
//            };

//从cookie中获取数据
        function getCookie(cookie_name) {
          var result = "";
          var allcookies = document.cookie;
          var cookie_pos = allcookies.indexOf(cookie_name);
          if (cookie_pos != -1)   
          {
              cookie_pos += cookie_name.length + 1;
              var cookie_end = allcookies.indexOf(";", cookie_pos);
             if (cookie_end == -1)
             {           
                cookie_end = allcookies.length;       
              }
            result = unescape(allcookies.substring(cookie_pos, cookie_end));
          }
        return result;
       }

在js中读取//读txt文件   使用到的微软插件时：activeObject;
        function readFile(filename) {
            var fso = new ActiveXObject("Scripting.FileSystemObject");
            var f = fso.OpenTextFile(filename, 1);
            var s = "";
            while (!f.AtEndOfStream)
                s += f.ReadLine() + " ";
            f.Close();
            return s;
        }

 //通过元素的class获取对应的元素
    function getElementsByClassName(n) {
        var classElements = [], allElements = document.getElementsByTagName('*');
        for (var i = 0; i < allElements.length; i++) {
            if (allElements[i].className == n) {
                classElements[classElements.length] = allElements[i];
            }
        }
        return classElements;
    }