(function($) {    
    // the code of this function is from     
    // http://lucassmith.name/pub/typeof.html    
    $.type = function(o) {    
        var _toS = Object.prototype.toString;    
        var _types = {    
            'undefined': 'undefined',    
            'number': 'number',    
            'boolean': 'boolean',    
            'string': 'string',    
            '[object Function]': 'function',    
            '[object RegExp]': 'regexp',    
            '[object Array]': 'array',    
            '[object Date]': 'date',    
            '[object Error]': 'error'    
        };    
        return _types[typeof o] || _types[_toS.call(o)] || (o ? 'object' : 'null');    
    };    
    // the code of these two functions is from mootools    
    // http://mootools.net    
    var $specialChars = { '\b': '\\b', '\t': '\\t', '\n': '\\n', '\f': '\\f', '\r': '\\r', '"': '\\"', '\\': '\\\\' };    
    var $replaceChars = function(chr) {    
        return $specialChars[chr] || '\\u00' + Math.floor(chr.charCodeAt() / 16).toString(16) + (chr.charCodeAt() % 16).toString(16);    
    };    
    $.toJSON = function(o) {    
        var s = [];    
        switch ($.type(o)) {    
            case 'undefined':    
                return '""';    
                break;    
            case 'null':    
                return 'null';    
                break;    
            case 'number':    
            case 'boolean':    
            case 'date':    
            case 'function':    
                return o.toString();    
                break;    
            case 'string':    
                return '"' + o.replace(/[\x00-\x1f\\"]/g, $replaceChars) + '"';    
                break;    
            case 'array':    
                for (var i = 0, l = o.length; i < l; i++) {    
                    s.push($.toJSON(o[i]));    
                }    
                return '[' + s.join(',') + ']';    
                break;    
            case 'error':    
            case 'object':    
                for (var p in o) {    
                    s.push(p + ':' + $.toJSON(o[p]));    
                }    
                return '{' + s.join(',') + '}';    
                break;    
            default:    
                return '';    
                break;    
        }    
    };    
    $.evalJSON = function(s) {    
        if ($.type(s) != 'string' || !s.length) return null;    
        return eval('(' + s + ')');    
    };    
})(jQuery);