新建一个web窗体的有关问题

新建一个web窗体的问题
新建一个web窗体，default.aspx页面不做定义
在default.cs文件中创建
DropDownList   oSelectAppearance   =   new   DropDownList();
DropDownList   oSelectSpeed   =   new   DropDownList();
下拉框，设置自动回发
oSelectAppearance.AutoPostBack   =   true;
oSelectSpeed.AutoPostBack   =   true;

这时候要在后台设置他们的OnSelectedIndexChanged事件应该怎样设置呢~？
在msdn帮助写的该OnSelectedIndexChanged事件是protected的阿~

求教各位大大了

[解决办法]
DropDownList oSelectAppearance = new DropDownList();
DropDownList oSelectSpeed = new DropDownList();

oSelectAppearance.SelectedIndexChanged += new EventHandler(oSelectAppearance_SelectedIndexChanged);


void oSelectAppearance_SelectedIndexChanged(object sender, EventArgs e)
{
throw new Exception( "The method or operation is not implemented. ");
}
[解决办法]
protected void Page_Load(object sender, EventArgs e)
{
DropDownList1.SelectedIndexChanged += new EventHandler(DropDownList1_SelectedIndexChanged);
}

void DropDownList1_SelectedIndexChanged(object sender, EventArgs e)
{
throw new Exception( "The method or operation is not implemented. ");
}