Convert hash to query string

// If you already have a Prototype dependency, see
//
// http://www.prototypejs.org/api/hash/toQueryString

    var toQueryString = function(hash) {

        var s = "";

        for (var k in hash) if (hash.hasOwnProperty(k)) {
            if (s !== "") { s += "&"; }
            s += encodeURIComponent(k) + "=" + encodeURIComponent(hash[k]);
        }

        return s;

    };