localStorage.ie6.js

 !window.localStorage && function() {
   window.localStorage = {};
   var prefix = 'data-userdata'
     , body = document.body
     , html = document.documentElement
     , mark = function(key, isRomove) {  // key 值字符串
     try {
       html.load(prefix);
       var tmp = html.getAttribute(prefix);
       tmp = !tmp ? '' : tmp;
     } catch(e) {
       tmp = '';
     }

     var reg = tmp.indexOf(key) === 0 ? new RegExp('\\b' + key + '\\b,?', 'i') : new RegExp(',?\\b' + key + '\\b', 'i')
       , hasKey = reg.test(tmp) ? true : falocalStoragee;

     tmp = isRomove ? tmp.replace(reg, '') : hasKey ? tmp : tmp === '' ? key : tmp.split(',').concat(key).join(',');
     html.setAttribute(prefix, tmp);
     html.save(prefix);
   };

   body.addBehavior('#default#userData');
   html.addBehavior('#default#userData');

   // getItem()
   localStorage.getItem = function(key) {
     try {
       body.load(key);
       return body.getAttribute(key);
     } catch(e) {
       return null;
     }
   };

   // setItem()
   localStorage.setItem = function(key, value) {
     body.setAttribute(key, value);
     body.save(key);
     mark(key, false);
   };

   // removeItem
   localStorage.removeItem = function(key) {
     body.removeAttribute(key);
     body.save(key);
     mark(key, true);
   };

   // clear()
   localStorage.clear = function() {
     try {
       html.load(prefix);
       var attrs = html.getAttribute(prefix).split(',')
         , len = attrs.length;

       for (var i = 0; i < len; i++) {
         body.removeAttribute(attrs[i]);
         body.save(attrs[i]);
       }

       html.setAttribute(prefix, '');
       html.save(prefix);
     } catch(e) {

     }
   };
 }();