private void DataGrid2_UpdateCommand_1(object source, System.Web.UI.WebControls.DataGridCommandEventArgs e)
        {
            try
            {
                string strConnection = "data source=(local);user id=sa; password = sa;initial catalog=cjg";
                SqlConnection myConn = new SqlConnection(strConnection);
                string shipname1=((TextBox)e.Item.Cells[3].Controls[0]).Text.Trim();
                string companyname1=((TextBox)e.Item.Cells[4].Controls[0]).Text.Trim();
                string portofregistry1=((TextBox)e.Item.Cells[5].Controls[0]).Text.Trim();
                ////////////////////////////////////////////////////////////////////////////
                string resorttime1=((TextBox)e.Item.Cells[6].Controls[0]).Text.Trim();
                string resortplace1=((TextBox)e.Item.Cells[7].Controls[0]).Text.Trim();
                string pk1 = ((TextBox)e.Item.Cells[8].Controls[0]).Text.Trim();
               
               
                string str = "update [resort] set [companyname]='"+companyname1+"',[portofregistry]='"+portofregistry1+"',[resorttime]='"+resorttime1+"',[resortplace]='"+resortplace1+"' [pk] = '"+pk1+"' where [shipname] = '"+shipname1+"'";
                SqlCommand   cmd   =   new SqlCommand(str,myConn);  
                myConn.Open();  
                cmd.ExecuteNonQuery();  
                myConn.Close();  
                this.DataGrid2.EditItemIndex=-1;
                this.BindData();
            }
            catch(Exception ex)
            {
                throw ex;
            }
        }
            }
        }
这段程序，编译成功后，点击编辑，更新，出现下面的错误，该如何更正呢？“/WebApplication1”应用程序中的服务器错误。
--------------------------------------------------------------------------------
指定的参数已超出有效值的范围。参数名: index
说明: 执行当前 Web 请求期间，出现未处理的异常。请检查堆栈跟踪信息，以了解有关该错误以及代码中导致错误的出处的详细信息。

异常详细信息: System.ArgumentOutOfRangeException: 指定的参数已超出有效值的范围。参数名: index
源错误:

行 342：            catch(Exception ex)
行 343：            {
行 344：                throw ex;
行 345：            }
行 346：        }


源文件: c:\inetpub\wwwroot\webapplication1\resort.aspx.cs    行: 344

堆栈跟踪:

[ArgumentOutOfRangeException: 指定的参数已超出有效值的范围。
参数名: index]
   WebApplication1.WebForm1.DataGrid2_UpdateCommand_1(Object source, DataGridCommandEventArgs e) in c:\inetpub\wwwroot\webapplication1\resort.aspx.cs:344
   System.Web.UI.WebControls.DataGrid.OnUpdateCommand(DataGridCommandEventArgs e)
   System.Web.UI.WebControls.DataGrid.OnBubbleEvent(Object source, EventArgs e)
   System.Web.UI.Control.RaiseBubbleEvent(Object source, EventArgs args)
   System.Web.UI.WebControls.DataGridItem.OnBubbleEvent(Object source, EventArgs e)
   System.Web.UI.Control.RaiseBubbleEvent(Object source, EventArgs args)
   System.Web.UI.WebControls.LinkButton.OnCommand(CommandEventArgs e)
   System.Web.UI.WebControls.LinkButton.System.Web.UI.IPostBackEventHandler.RaisePostBackEvent(String eventArgument)
   System.Web.UI.Page.RaisePostBackEvent(IPostBackEventHandler sourceControl, String eventArgument)
   System.Web.UI.Page.RaisePostBackEvent(NameValueCollection postData)
   System.Web.UI.Page.ProcessRequestMain()