Edit Data in Datagrid

Question

hi all, in 2005 C# Express, OnUpdateCommand never reached. code is below. void grdOrderDetail_UpdateCommand(object source, DataGridCommandEventArgs e) { // never reached this statement Response.Write( grdOrderDetail.DataKeys[ e.Item.ItemIndex ].ToString() ); grdOrderDetail.DataBind(); } void grdOrderDetail_EditCommand(object source, DataGridCommandEventArgs e) { grdOrderDetail.EditItemIndex = e.Item.ItemIndex; grdOrderDetail.DataBind(); } void grdOrderDetail_CancelCommand(object source, DataGridCommandEventArgs e) { grdOrderDetail.EditItemIndex = -1; grdOrderDetail.DataBind(); } pls help, how can i solve...