Menu: File > Close
Default Shortcut Key: Alt+X
Macro function: Close()
The Close command is used to close the file in the active editor window. If unsaved changes have been made to the file, a dialog box will first appear to alert you to this fact. You will then be able to choose whether to save the changes before closing, close without saving, or cancel the Close operation altogether.
You can quickly tell whether a file has unsaved changes by looking for an asterisk (*) to the left of its name in the title bar, or on its File Tab.
A file can also be closed by clicking the 'X' box in the upper right corner of its window. When a file's window is maximized, the 'X' box will be located at the far right of the main menu bar.
If you would prefer that Boxer be minimized automatically when the last file is closed, there is a checkbox on the Configure | Preferences | Other options page to achieve this. The option is titled Minimize Boxer when closing last file.