private void AddNewRow()
        {
            //MessageBox.Show("AddNewRow");       //20130730,SKK
            if (xref == null)
            {
                return;
            }

            //add a new shared memory variable at the end of the list
            xref.GetSharedMemoryManager().AddNewShmVarWithDefaultValue();

            //first set focus
            ShmVarDataGrid.Focus();

            //select the last element of the list
            ShmVarDataGrid.SelectedItem = ListOfShmVariables.Last();

            //then create a new cell info, with the item we wish to edit and the column number of the cell we want in edit mode
            DataGridCellInfo cellInfo = new DataGridCellInfo(ShmVarDataGrid.SelectedItem, ShmVarDataGrid.Columns[0]);

            //set the cell to be the active one
            ShmVarDataGrid.CurrentCell = cellInfo;

            //scroll the item into view
            ShmVarDataGrid.ScrollIntoView(ShmVarDataGrid.SelectedItem);

            //begin the edit
            ShmVarDataGrid.BeginEdit();
        }