Date.prototype.format = function(format) {

    /*

     * eg:format="yyyy-MM-dd hh:mm:ss";

     */

    var o = {

        "M+" : this.getMonth() + 1, // month

        "d+" : this.getDate(), // day

        "h+" : this.getHours(), // hour

        "m+" : this.getMinutes(), // minute

        "s+" : this.getSeconds(), // second

        "q+" : Math.floor((this.getMonth() + 3) / 3), // quarter

        "S" : this.getMilliseconds()

        // millisecond

    };  

    if (/(y+)/.test(format)) {

        format = format.replace(RegExp.$1, (this.getFullYear() + "").substr(4

                        - RegExp.$1.length));

    }  

    for (var k in o) {

        if (new RegExp("(" + k + ")").test(format)) {

            format = format.replace(RegExp.$1, RegExp.$1.length == 1

                            ? o[k]

                            : ("00" + o[k]).substr(("" + o[k]).length));

        }

    }

    return format;

};