parse query string to object

query.js

function parseQuery(querystring){
   querystring = querystring.split('&');
   var query = {};
   for (var i = querystring.length - 1; i > -1; i--) {
      var kv = querystring[i].split('=');
      var key = decodeURIComponent(kv[0]);
      query[key] = decodeURIComponent(kv[1]);
   }
   return query;
}

function stringifyQuery(query) {
    var ret = [];
    for (var k in query) {
        ret.push(encodeURIComponent(k) + '=' + encodeURIComponent(query[k]));
    }

    return ret.join('&');  
}