final RowBandingFunction function = findRowbandingFunction(activeContext);
final AbstractReportDefinition report = activeContext.getReportDefinition();
if (function == null)
{
final RowBandingFunction newFunction = new RowBandingFunction();
if (dialog.performEdit(newFunction))
{
report.getExpressions().add(newFunction);
activeContext.getUndo().addChange(ActionMessages.getString("EditRowBandingAction.Text"),
new ExpressionAddedUndoEntry(report.getExpressions().size() - 1, newFunction));
report.notifyNodeChildAdded(function);