When an exiting file is opened or a new file is created, the Designer Window will be divided vertically into two panes. The left pane is the card pane and it contains three pages: Design, Code, and XML Tree. In the Design page the names of the cards in the file will be displayed. The XML code of the file will be displayed if you select the Code page. You can edit the code manually and then compile it by selecting the compile icon in the Tool Bar. When you select the tree page, the file will be displayed as an inverted tree.