JavaScript实现年月日选择器绑定HTML下拉框

<script type="text/javascript">
function DateSelector(selYear, selMonth, selDay)
{
    this.selYear = selYear;
    this.selMonth = selMonth;
    this.selDay = selDay;
    this.selYear.Group = this;
    this.selMonth.Group = this;
    // 给年份、月份下拉菜单添加处理onchange事件的函数
    if(window.document.all != null) // IE
    {
        this.selYear.attachEvent("onchange", DateSelector.Onchange);
        this.selMonth.attachEvent("onchange", DateSelector.Onchange);
    }
    else // Firefox
    {
        this.selYear.addEventListener("change", DateSelector.Onchange, false);
        this.selMonth.addEventListener("change", DateSelector.Onchange, false);
    }

    if(arguments.length == 4) // 如果传入参数个数为4，最后一个参数必须为Date对象
        this.InitSelector(arguments[3].getFullYear(), arguments[3].getMonth() + 1, arguments[3].getDate());
    else if(arguments.length == 6) // 如果传入参数个数为6，最后三个参数必须为初始的年月日数值
        this.InitSelector(arguments[3], arguments[4], arguments[5]);
    else // 默认使用当前日期
    {
        var dt = new Date();
        this.InitSelector(dt.getFullYear(), dt.getMonth() + 1, dt.getDate());
    }
}

// 增加一个最大年份的属性
DateSelector.prototype.MinYear = 1900;

// 增加一个最大年份的属性
DateSelector.prototype.MaxYear = (new Date()).getFullYear();

// 初始化年份
DateSelector.prototype.InitYearSelect = function()
{
    // 循环添加OPION元素到年份select对象中
    for(var i = this.MaxYear; i >= this.MinYear; i--)
    {
        // 新建一个OPTION对象
        var op = window.document.createElement("OPTION");
        
        // 设置OPTION对象的值
        op.value = i;
        
        // 设置OPTION对象的内容
        op.innerHTML = i;
        
        // 添加到年份select对象
        this.selYear.appendChild(op);
    }
}

// 初始化月份
DateSelector.prototype.InitMonthSelect = function()
{