As we have seen in section 1.2.1, the TixControl widget is composed of several widgets: one label widget, one entry widget and two button widgets. These ``widgets inside mega-widgets'' are called subwidgets in the Tix terminology. We will often have the need to access these subwidgets. For example, sometimes we need to change the configuration options of the subwidgets. In other cases, we may need to interact with the subwidgets directly.