为什么vs.2003自身产生的代码也会出错,真的很急!请帮帮忙,在这谢谢了~

using System;
using System.Collections;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Web;
using System.Web.SessionState;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.HtmlControls;
using System.Data.SqlClient;
using System.Configuration;
namespace WebApplication1
{
/// <summary>
/// userlist 的摘要说明。
/// </summary>
public class userlist : System.Web.UI.Page
{
  protected System.Web.UI.WebControls.DataGrid dgd_userlist;
  protected System.Web.UI.WebControls.TextBox txb_uid;
  protected System.Web.UI.WebControls.Button btn_search;
  protected System.Web.UI.WebControls.HyperLink hlk_citylist;
  protected System.Web.UI.WebControls.HyperLink HyperLink2;  private void Page_Load(object sender, System.EventArgs e)
  {
   if(!IsPostBack)BindGrid();
   
    // 在此处放置用户代码以初始化页面
  }
  public void BindGrid()
  {
   
    string strconn=ConfigurationSettings.AppSettings["dsn"];
    SqlConnection cn=new SqlConnection(strconn); 
    cn.Open();
    SqlDataAdapter da=new SqlDataAdapter("userlist",cn);
                DataSet ds=new DataSet();
    da.Fill(ds);
    dgd_userlist.DataSource=ds;
    dgd_userlist.DataBind();
    cn.Close();
   
  }  #region Web 窗体设计器生成的代码
  override protected void OnInit(EventArgs e)
  {
   //
   // CODEGEN: 该调用是 ASP.NET Web 窗体设计器所必需的。
   //
   InitializeComponent();
   base.OnInit(e);
  }
  
  /// <summary>
  /// 设计器支持所需的方法 - 不要使用代码编辑器修改
  /// 此方法的内容。
  /// </summary>
  private void InitializeComponent()
  {    
   this.btn_search.Click += new System.EventHandler(this.Page_Load);
   this.dgd_userlist.PageIndexChanged += new System.Web.UI.WebControls.DataGridPageChangedEventHandler(this.dgd_userlist_PageIndexChanged);
   this.dgd_userlist.EditCommand += new System.Web.UI.WebControls.DataGridCommandEventHandler(this.dgd_userlist_EditCommand);
   this.dgd_userlist.UpdateCommand += new System.Web.UI.WebControls.DataGridCommandEventHandler(this.dgd_userlist_UpdateCommand);
   this.dgd_userlist.DeleteCommand += new System.Web.UI.WebControls.DataGridCommandEventHandler(this.dgd_userlist_DeleteCommand);
   this.dgd_userlist.Load += new System.EventHandler(this.Page_Load);
   this.dgd_userlist.SelectedIndexChanged += new System.EventHandler(this.dgd_userlist.SelectedIndexChanged);
   this.Load += new System.EventHandler(this.Page_Load);  }
  #endregion  private void dgd_userlist_EditCommand(object source, System.Web.UI.WebControls.DataGridCommandEventArgs e)
  {
   dgd_userlist.EditItemIndex=(int)e.Item.ItemIndex;
   BindGrid();
  
  }  private void dgd_userlist_UpdateCommand(object source, System.Web.UI.WebControls.DataGridCommandEventArgs e)
  {
   string strconn=ConfigurationSettings.AppSettings["dsn"];
   SqlConnection cn=new SqlConnection(strconn);
   cn.Open();
   SqlCommand cm=new SqlCommand("usermodifyForAdmin",cn);
   cm.CommandType=CommandType.StoredProcedure;
   cm.Parameters.Add("@UID",SqlDbType.VarChar);
   cm.Parameters.Add(new SqlParameter("@UPower",SqlDbType.Int));
   string uidvalue=e.Item.Cells[1].Text.ToString();
   cm.Parameters["@UID"].Value=uidvalue;
   string upowervalue=((DropDownList)e.Item.FindControl
   ("ddl_upower")).SelectedItem.Value.ToString();
   cm.Parameters["@UPower"].Value=Convert.ToInt16(upowervalue);
   cm.ExecuteNonQuery();
   dgd_userlist.EditItemIndex=-1;
   BindGrid();
  }  private void dgd_userlist_DeleteCommand(object source, System.Web.UI.WebControls.DataGridCommandEventArgs e)
  {
   string strconn=ConfigurationSettings.AppSettings["dsn"];
   SqlConnection cn=new SqlConnection(strconn);
   cn.Open();
   string userdelete="delete * from users where UID=@UID ";
   SqlCommand cm=new SqlCommand(userdelete,cn);
   cm.Parameters.Add("@UID",SqlDbType.VarChar);
   string uidvalue=e.Item.Cells[1].Text.ToString();
   cm.Parameters["@UID"].Value=uidvalue;
   cm.ExecuteNonQuery();
   dgd_userlist.EditItemIndex=-1;
   BindGrid();
  }  private void dgd_userlist_PageIndexChanged(object source, System.Web.UI.WebControls.DataGridPageChangedEventArgs e)
  {
   dgd_userlist.CurrentPageIndex=e.NewPageIndex;
   BindGrid();
  
  }  private void btn_searchClick(object sender, System.EventArgs e)
  {
   string varuid=txb_uid.Text.ToString();
   Response.Redirect("userdetail.aspx?uid="+varuid);
    }    
}
}出错提示!c:\inetpub\wwwroot\WebApplication1\userlist.aspx.cs(69): 事件“System.Web.UI.WebControls.BaseDataList.SelectedIndexChanged”只能出现在 += 或 -= 的左边