Hi,

Try to use this javacritpt code:

function AfterCellUpdate(gridName,cellID)
        {
            var cell = igtbl_getCellById(cellID)
            if (cell)
            {
                var parentValue = cell.getValue();
                var children = cell.Row.getChildRows();
                if (children && cell.Column.ColumnType == 3)
                {
                    for (var i = 0; i < children.length; i++)
                    {
                        var row = igtbl_getRowById(children[i].id);
                        if (row)
                        {
                            var childCell = row.getCellFromKey('COLUMNKEY')
                            if (childCell)
                            {
                                childCell.setValue(parentValue);
                            }
                        }
                    }
                }
            }
        } 

And on uwg's propertie ClienteSideEvents set this:

<ClientSideEvents AfterCellUpdateHandler="AfterCellUpdate" />

I hope this hepful.