System.IndexOutOfRangeException: There is no row at position 0. at System.Data.RBTree`1.GetNodeByIndex(Int32 userIndex) at System.Data.RBTree`1.get_Item(Int32 index) at System.Data.DataRowCollection.get_Item(Int32 index) at NGOCLONG18S.UI.MainFC.GetRootNevigate(Int32 CurentTabID, DataTable dt) at Default.Page_Load(Object sender, EventArgs e) Foman