js代码用的好好的突然报错了，求大神指教

Question

报错信息：
Uncaught TypeError: this.onStart is not a function
at Object.Start (focus.js:83)
at window.onload (focus.js:124)

js原码：// JavaScript Document
//计算idslider2的宽度开始
var kuan1=0;
var kuand=document.getElementById('idSlider2')
var kuan=document.getElementById('idSlider2').getElementsByTagName("li");
var tpz=kuan.length;//图片总个数
for(var i=0; i<kuan.length; i++){
kuan1+=400;
}
kuand.style.width=kuan1+'px';
//计算结束

var keVar = function (id) {
return "string" == typeof id ? document.getElementById(id) : id;
};

var Class = {
create: function() {
return function() {
this.initialize.apply(this, arguments);
}
}
}

Object.extend = function(destination, source) {
for (var property in source) {
destination[property] = source[property];
}
return destination;
}

var TransformView = Class.create();
TransformView.prototype = {
//容器对象,滑动对象,切换参数,切换数量
initialize: function(container, slider, parameter, count, options) {
if(parameter <= 0 || count <= 0) return;
var oContainer = keVar(container), oSlider = keVar(slider), oThis = this;

this.Index = 0;//当前索引

this._timer = null;//定时器
this._slider = oSlider;//滑动对象
this._parameter = parameter;//切换参数
this._count = count || 0;//切换数量
this._target = 0;//目标参数

this.SetOptions(options);

this.Up = !!this.options.Up;
this.Step = Math.abs(this.options.Step);
this.Time = Math.abs(this.options.Time);
this.Auto = !!this.options.Auto;
this.Pause = Math.abs(this.options.Pause);
this.onStart = this.options.onStart;
this.onFinish = this.options.onFinish;

oContainer.style.overflow = "hidden";
oContainer.style.position = "relative";

oSlider.style.position = "absolute";
oSlider.style.top = oSlider.style.left = 0;

},
//设置默认属性
SetOptions: function(options) {
this.options = {//默认值
Up: true,//是否向上(否则向左)
Step: 5,//滑动变化率
Time: 10,//滑动延时
Auto: true,//是否自动转换
Pause: 3000,//停顿时间(Auto为true时有效)
onStart: function(){},//开始转换时执行
onFinish: function(){}//完成转换时执行
};
Object.extend(this.options, options || {});
},
//开始切换设置
Start: function() {
if(this.Index < 0){
this.Index = this._count - 1;
} else if (this.Index >= this._count){ this.Index = 0; }

this._target = -1 * this._parameter * this.Index;
this.onStart();
this.Move();

},
//移动
Move: function() {
clearTimeout(this._timer);
var oThis = this, style = this.Up ? "top" : "left", iNow = parseInt(this._slider.style[style]) || 0, iStep = this.GetStep(this._target, iNow);

if (iStep != 0) {
    this._slider.style[style] = (iNow + iStep) + "px";
    this._timer = setTimeout(function(){ oThis.Move(); }, this.Time);
} else {
    this._slider.style[style] = this._target + "px";
    this.onFinish();
    if (this.Auto) { this._timer = setTimeout(function(){ oThis.Index++; oThis.Start(); }, this.Pause); }
}

},
//获取步长
GetStep: function(iTarget, iNow) {
var iStep = (iTarget - iNow) / this.Step;
if (iStep == 0) return 0;
if (Math.abs(iStep) < 1) return (iStep > 0 ? 1 : -1);
return iStep;
},
//停止
Stop: function(iTarget, iNow) {
clearTimeout(this._timer);
this._slider.style[this.Up ? "top" : "left"] = this._target + "px";
}
};

window.onload=function(){
function Each(list, fun){
for (var i = 0, len = list.length; i < len; i++) { fun(list[i], i); }
};

var objs2 = keVar("idNum2").getElementsByTagName("li");
var tv2 = new TransformView("idTransformView2", "idSlider2", 400, tpz, {    
    onStart: function(){ Each(objs2, function(o, i){ o.className = tv2.Index == i ? "on" : ""; }) },//按钮样式
    Up: false
});//6是轮播总数
tv2.Start();
Each(objs2, function(o, i){
    o.onmouseover = function(){
        o.className = "on";
        tv2.Auto = false;
        tv2.Index = i;
        tv2.Start();
    }
    o.onmouseout = function(){
        o.className = "";
        tv2.Auto = true;
        tv2.Start();
    }
})

}

Answer 1

F12 浏览器调试下看看错误是什么呢？