/**
     *
     * Base64 encode / decode
     *
     * @author haitao.tu
     * @date  2010-04-26
     * @email tuhaitao@foxmail.com
     *
     */
    function Base64() {

        // private property
        _keyStr = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";

        // public method for encoding
        this.encode = function (input) {
            var output = "";
            var chr1, chr2, chr3, enc1, enc2, enc3, enc4;
            var i = 0;
            input = _utf8_encode(input);
            while (i < input.length) {
                chr1 = input.charCodeAt(i++);
                chr2 = input.charCodeAt(i++);
                chr3 = input.charCodeAt(i++);
                enc1 = chr1 >> 2;
                enc2 = ((chr1 & 3) << 4) | (chr2 >> 4);
                enc3 = ((chr2 & 15) << 2) | (chr3 >> 6);
                enc4 = chr3 & 63;
                if (isNaN(chr2)) {
                    enc3 = enc4 = 64;
                } else if (isNaN(chr3)) {
                    enc4 = 64;
                }
                output = output +
                    _keyStr.charAt(enc1) + _keyStr.charAt(enc2) +
                    _keyStr.charAt(enc3) + _keyStr.charAt(enc4);
            }
            return output;
        }

        // public method for decoding
        this.decode = function (input) {
            var output = "";
            var chr1, chr2, chr3;
            var enc1, enc2, enc3, enc4;
            var i = 0;
            input = input.replace(/[^A-Za-z0-9\+\/\=]/g, "");
            while (i < input.length) {
                enc1 = _keyStr.indexOf(input.charAt(i++));
                enc2 = _keyStr.indexOf(input.charAt(i++));
                enc3 = _keyStr.indexOf(input.charAt(i++));
                enc4 = _keyStr.indexOf(input.charAt(i++));
                chr1 = (enc1 << 2) | (enc2 >> 4);
                chr2 = ((enc2 & 15) << 4) | (enc3 >> 2);
                chr3 = ((enc3 & 3) << 6) | enc4;
                output = output + String.fromCharCode(chr1);
                if (enc3 != 64) {
                    output = output + String.fromCharCode(chr2);
                }
                if (enc4 != 64) {
                    output = output + String.fromCharCode(chr3);
                }
            }
            output = _utf8_decode(output);
            return output;
        }

        // private method for UTF-8 encoding
        _utf8_encode = function (string) {
            string = string.replace(/\r\n/g,"\n");
            var utftext = "";
            for (var n = 0; n < string.length; n++) {
                var c = string.charCodeAt(n);
                if (c < 128) {
                    utftext += String.fromCharCode(c);
                } else if((c > 127) && (c < 2048)) {
                    utftext += String.fromCharCode((c >> 6) | 192);
                    utftext += String.fromCharCode((c & 63) | 128);
                } else {
                    utftext += String.fromCharCode((c >> 12) | 224);
                    utftext += String.fromCharCode(((c >> 6) & 63) | 128);
                    utftext += String.fromCharCode((c & 63) | 128);
                }

            }
            return utftext;
        }

        // private method for UTF-8 decoding
        _utf8_decode = function (utftext) {
            var string = "";
            var i = 0;
            var c = c1 = c2 = 0;
            while ( i < utftext.length ) {
                c = utftext.charCodeAt(i);
                if (c < 128) {
                    string += String.fromCharCode(c);
                    i++;
                } else if((c > 191) && (c < 224)) {
                    c2 = utftext.charCodeAt(i+1);
                    string += String.fromCharCode(((c & 31) << 6) | (c2 & 63));
                    i += 2;
                } else {
                    c2 = utftext.charCodeAt(i+1);
                    c3 = utftext.charCodeAt(i+2);
                    string += String.fromCharCode(((c & 15) << 12) | ((c2 & 63) << 6) | (c3 & 63));
                    i += 3;
                }
            }
            return string;
        }
    }

    Date.prototype.Format = function (fmt) {
        var o = {
            "M+": this.getMonth() + 1, //月份
            "d+": this.getDate(), //日
            "H+": this.getHours(), //小时
            "m+": this.getMinutes(), //分
            "s+": this.getSeconds(), //秒
            "q+": Math.floor((this.getMonth() + 3) / 3), //季度
            "S": this.getMilliseconds() //毫秒
        };
        if (/(y+)/.test(fmt)) fmt = fmt.replace(RegExp.$1, (this.getFullYear() + "").substr(4 - RegExp.$1.length));
        for (var k in o)
            if (new RegExp("(" + k + ")").test(fmt)) fmt = fmt.replace(RegExp.$1, (RegExp.$1.length == 1) ? (o[k]) : (("00" + o[k]).substr(("" + o[k]).length)));
        return fmt;
    }

    function getWeek() {
        //按周日为一周的最后一天计算
        var date = new Date();
        //今天是这周的第几天
        var today = date.getDay();
        //上周日距离今天的天数（负数表示）
        var stepSunDay = -today + 1;
        // 如果今天是周日
        if (today == 0) {
            stepSunDay = -7;
        }
        // 周一距离今天的天数（负数表示）
        var stepMonday = 7 - today;
        var time = date.getTime();
        var monday = new Date(time + stepSunDay * 24 * 3600 * 1000);
        var sunday = new Date(time + stepMonday * 24 * 3600 * 1000);
        //本周一的日期 （起始日期）
        var startDate = transferDate(monday); // 日期变换
        //本周日的日期 （结束日期）
        var endDate = transferDate(sunday); // 日期变换
        return startDate + '=' + endDate;
    }
    function transferDate(date) {
        // 年
        var year = date.getFullYear();
        // 月
        var month = date.getMonth() + 1;
        // 日
        var day = date.getDate();
        if (month >= 1 && month <= 9) {
            month = "0" + month;
        }
        if (day >= 0 && day <= 9) {
            day = "0" + day;
        }
        var dateString = year + '-' + month + '-' + day;
        return dateString;
    }


    // 获取前后几天的时间
    function getDay(day){
        var today = new Date();
        var targetday_milliseconds=today.getTime() + 1000*60*60*24*day;
        today.setTime(targetday_milliseconds); //注意，这行是关键代码
        var tYear = today.getFullYear();
        var tMonth = today.getMonth();
        var tDate = today.getDate();
        tMonth = doHandleMonth(tMonth + 1);
        tDate = doHandleMonth(tDate);
        return tYear+"-"+tMonth+"-"+tDate;
    }
    function doHandleMonth(month){
        var m = month;
        if(month.toString().length == 1){
            m = "0" + month;
        }
        return m;
    }