gistfile1.js

var loc;
 
(function locdef() {
  function findParam(name) {
    return new RegExp(name + '=([^&#]*)');
  }
  loc = {
    updateParam : function updateParam(name, val) {
      var l = location.href,
          s = name + '=' + val;
 
      return location.href = l.match(findParam(name)) ? l.replace(findParam(name), s) :
                             l.match(/\?/)            ? l.replace(/\?/, '?' + s + '&') :
                             l.match(/#/)             ? l.replace(/#/,  '?' + s + '#') :
                                                        l + '?' + s;
    },
    getParam : function getParam(name) {
      return (location.href.match(findParam(name))||{})[1] || "";
    }
  }
})();