var QueryString = (function() {


    parse = function() {
        var vars = [],
            hash;
        var q = document.URL.split('?')[1];
        if (q != undefined) {
            q = q.split('&');
            for (var i = 0; i < q.length; i++) {
                hash = q[i].split('=');
                vars.push(hash[1]);
                vars[hash[0]] = hash[1];
            }
        }
        return vars;
    }


    update = function(key, value) {
        /* https://gist.github.com/excalq/2961415 */
        var baseUrl = [location.protocol, '//', location.host, location.pathname].join(''),
            urlQueryString = document.location.search,
            newParam = key + '=' + value,
            params = '?' + newParam;

        // If the "search" string exists, then build params from it
        if (urlQueryString) {
            keyRegex = new RegExp('([\?&])' + key + '[^&]*');

            // If param exists already, update it
            if (urlQueryString.match(keyRegex) !== null) {
                params = urlQueryString.replace(keyRegex, "$1" + newParam);
            } else { // Otherwise, add it to end of query string
                params = urlQueryString + '&' + newParam;
            }
        }
        window.history.replaceState({}, "", baseUrl + params);
    }


    return {
        Parse: parse,
        Set: update
    }

}());