VS2003下，datarid批量删除

private void BT_Del_Click(object sender, System.EventArgs e)
  {
   string delstr = "";
   for (int i = 0; i < DG.Items.Count; i++)
   {
    CheckBox cb = (CheckBox)DG.Items[i].FindControl("CK");
    if (cb.Checked == true)
    {
     if (delstr.ToString().Trim() == "")
     {
      delstr += DG.DataKeys[i].ToString();
     }
     else
     {
      delstr += "," + DG.DataKeys[i].ToString();
     }
    }//if end
   }//for end
   //delete
   try
   {
    //delete
    DBOperate.ExcuteSql("Delete From XZNews Where XZID In ("+delstr+")");
    Response.Write("<script language=javascript>alert('删除成功!');</script>");
    Response.Write("<script language=javascript>window.location.href=window.location.href;</script>");
   }
   catch (Exception)
   {
    Response.Write("<script language=javascript>alert('Error,删除失败!');</script>");
   }
  }