Javascript Ajax请求并不总是一致的

我一直在开发一个网站，将提供由人创建的时间表。我正在使用Alienware进行开发，ajax代码在笔记本电脑上一直运行良好。我正在使用IE。但是，如果我在三星智能电视或HTC U11手机上访问我的网站，Ajax就不一致了。它显示我正在请求的数据，但是，当我汇总一周的总小时数时，它有时会显示正确的小时数，有时会显示0小时（当用户计划一周时）。为什么设备之间不一致？我知道Ajax被推荐用于IE。不过，正如我所说，它有时会显示正确的每周总小时数，而其他时候它只会显示零。我的Alienware上没有出现此问题

我已经尝试使用onload而不是onreadystatechange。我已经将请求设置为异步和同步。在我的其他设备上，无论设置为true还是false，它都无法保持一致。我尝试过将其作为一种post和get方法，但两者都不一致。我的代码有什么问题

function getThisWeek(str5) {

    lastDate = new Date(str5);

    // getting dates for this week to be displayed...

    this.math = dayInput.length - 1;

    this.math0 = 0 - new Date(str5).getDay();

    // getting week total hour length, to determine how many times this code executes...
    weekSum = 0;
    totals = [];
    for (this.i = 0; this.i < weekTotalHours.length; this.i++) {

        str3 = this.i;
        this.date = new Date(str5);
        for (this.ii = (this.i * (7)) - new Date().getDay(); this.ii < (7 * (this.i + 1)) - new Date().getDay(); this.ii++) {

            totalHours = 0;

            this.date = new Date(str5);
            this.date = new Date(this.date.setDate(this.date.getDate() + (this.ii)));

            // which element position the total daily hours belongs to when displaying them...
            this.pos = this.ii + new Date().getDay();
            thisDayChart[this.pos].innerHTML = "";

                // displaying the date
                dayInput[this.pos].innerHTML = this.date.getDate();

                // highlighting today's date...
                if (this.date.getDate() == new Date(str5).getDate() && this.date.getMonth() == new Date().getMonth()) {
                dayInput[this.pos].style.color = "white";
                dayInput[this.pos].style.backgroundColor = "silver";
                dayInput[this.pos].style.borderRadius = "0px";
                thisDay[this.pos].style.border = "2px double lightblue";
                } else {
                dayInput[this.pos].style.color = "";
                dayInput[this.pos].style.backgroundColor = "";
                dayInput[this.pos].style.borderRadius = "";
                thisDay[this.pos].style.border = "";
                }

            // getting schedule from database...

            this.xmlhttp = new XMLHttpRequest();
            this.xmlhttp.pos = this.pos;
            this.xmlhttp.ipos = this.i;
            this.xmlhttp.d = months[this.date.getMonth()] + " " + this.date.getDate() + ", " + this.date.getFullYear();
            this.xmlhttp.onreadystatechange = function() {

                if (this.readyState == 4 && this.status == 200) {

                    //alert(this.responseText);

                    dayInput[this.pos].m = months[new Date(this.d).getMonth()];
                    dayInput[this.pos].weekDay = days[new Date(this.d).getDay()];

                    // how many weeks in the year is user...

                    this.islpyr = new Date(this.d);
                    this.islpyr = this.islpyr.setMonth(1);
                    this.islpyr = new Date(new Date(this.islpyr).setDate(29));

                    if (this.islpyr.getMonth() == 2) {
                    mlens[1] = 28;
                    } else {
                    mlens[1] = 29;
                    }

                    // getting total amount of days for the year...
                    this.yrlen = 0;
                    for (this.iii = 0; this.iii < mlens.length; this.iii++) {
                        this.yrlen += mlens[this.iii];
                    }

                    // getting total weeks
                    this.wklen = this.yrlen / 7;
                    this.wklen = Math.round(this.wklen);

                    this.week = 0;
                    for (this.iii = 0; this.iii < new Date(this.d).getMonth(); this.iii++) {

                        this.week += mlens[this.iii];

                    }
                    this.week += new Date(this.d).getDate();

                    this.week /= 7;
                    this.week = Math.round(this.week) + 1;
                    // rounding and displaying current week number...

                    if (new Date(this.d).getDay() == 0) {
                    myDayWrapper[this.ipos].weekLabel = "Week " + this.week + " of " + this.wklen;
                    }

                    if (this.pos == 0) {
                    weekDisplay[0].innerHTML = myDayWrapper[0].weekLabel;
                    }

                    // which day of the year it is... how many days in the year is the user...

                    this.yrpos = 0;
                    for (this.iv = 0; this.iv < new Date(this.d).getMonth(); this.iv++) {

                        this.yrpos += mlens[this.iv];

                    }

                    this.yrpos += new Date(this.d).getDate();

                    thisDayTitle[this.pos].innerHTML = "Day " + this.yrpos + " of " + this.yrlen;

                    totalHours = 0;

                    this.schedule = "" + this.responseText;

                    // if user is unscheduled, do this first... 'undefined' literally means there isn't a schedule for that specific day.
                    if (this.schedule.search("Undefined") >= 0) {

                        this.elem = document.createElement("div");
                        this.elem.setAttribute("class","not_scheduled");
                        this.elem.innerHTML = "Unscheduled";
                        thisDayChart[this.pos].appendChild(this.elem);

                        this.elem = document.createElement("div");
                        this.elem.setAttribute("class","pick_up_shift_btn");
                        this.elem.innerHTML = "Claim Shifts";
                        this.elem.i = this.pos;
                        this.elem.ipos = this.ipos;

                            this.elem.onclick = function() {

                                popUpWrap[1].style.display = "block";
                                this.datesd = [];
                                for (this.i = this.ipos * 7; this.i < 7 * (this.ipos + 1); this.i++) {
                                this.datesd.push(dayInput[this.i].innerHTML);
                                }

                                for (this.i = 0; this.i < 7; this.i++) {

                                shiftClaimDate[this.i].innerHTML = this.datesd[this.i];
                                popUpShiftDay[this.i].innerHTML = dayInput[this.i].weekDay;
                                this.strrr = "" + dayInput[this.i].m;
                                this.strrr = this.strrr.substring(0,3);
                                shiftClaimMonth[this.i].innerHTML = this.strrr;
                                }

                            }

                        thisDayChart[this.pos].appendChild(this.elem);

                        if (totals.length - 1 == this.pos) {
                        } else {
                        totals.push(0);
                        }

                    } else {

                        // getting daily total...

                        this.schedule = this.schedule.split(",");
                        for (this.iii = 0; this.iii < this.schedule.length; this.iii++) {

                            this.str = "" + this.schedule[this.iii];
                            this.str = this.str.split("=");

                            this.dateString = "December 22, 1991";
                            switch (this.str[0]) {

                                case "shift_start":

                                    this.start = new Date(this.dateString + " " + this.str[1]);
                                    this.end = this.schedule[this.schedule.length - 1] + "";
                                    this.end = this.end.split("=");
                                    this.end = new Date(this.dateString + " " + this.end[1]);

                                    this.hours = (this.end.getHours() - this.start.getHours()) * 60;
                                    this.hours = this.hours - (this.start.getMinutes() + this.end.getMinutes());
                                    this.hours /= 60;

                                    totalHours += this.hours;

                                    weekSum += totalHours;

                                break;

                                case "break_start":

                                    this.start = new Date(this.dateString + " " + this.str[1]);
                                    this.end = this.schedule[this.iii + 1] + "";
                                    this.end = this.end.split("=");
                                    this.end = new Date(this.dateString + " " + this.end[1]);

                                    this.hours = (this.end.getHours() - this.start.getHours()) * 60;
                                    this.hours = this.hours - (this.start.getMinutes() + this.end.getMinutes());
                                    this.hours /= 60;

                                    weekSum -= this.hours;
                                    totalHours -= this.hours;

                                    this.s = "s";
                                    if (totalHours == 1) {
                                    this.s = "";
                                    }


                                    thisDayChart[this.pos].innerHTML = totalHours + " hour" + this.s;

                                break;

                            }

                        }

                    }

                    weekTotalHours[this.ipos].innerHTML = "Week Total: " + weekSum;
                    //alert(weekSum);
                   // displaying hour totals...
                    if (new Date(this.d).getDay() == 6) {
                    weekSum = 0;
                    }
                    totalHours = 0;
                }


            }

            this.xmlhttp.open("GET","/js/data/schedule.html?date="+ months[this.date.getMonth()] + " " + this.date.getDate() + ", " + this.date.getFullYear(),false);
            this.xmlhttp.send();

        }

    }

}

函数获取本周（str5）{
lastDate=新日期（str5）；
//正在获取要显示的本周日期。。。
this.math=dayinport.length-1；
this.math0=0-新日期（str5）.getDay（）；
//正在获取周总小时长度，以确定此代码执行的次数。。。
周数=0；
总数=[]；
for（this.i=0；this.i=0）{
this.elem=document.createElement（“div”）；
此.elem.setAttribute（“类”、“未计划”）；
this.elem.innerHTML=“未计划”；