Methods for realizing advanced graphical user interface (GUI) in panel subunit. The present invention provides, in one embodiment, a button GUI element descriptor that defines a bitmap to be displayed when a button is out of focus and another bitmap to be displayed when the button is in focus. In another embodiment, the present invention provides a table GUI element descriptor that defines a table-like on screen display to be displayed on the contoller device. Another embodiment of the present invention provides a panel GUI element descriptor that includes a focused identifier attribute indicating a pre-determined element of the on-screen display as default focus. In this way, the target device would be able to control the default focus of the controller device when displaying an on-screen display. In yet another embodiment, the present invention provides a text GUI element descriptor that includes a font style attribute that dictates whether the text GUI element should be displayed as bold, underlined and/or reversed. By using these extended elements in panel subunit, more complicated and advanced GUI, such as an electronic programming guide (EPG) can be achieved.