You choose to execute the close command when you finish working with a file, but want to continue working with other files. To execute a close operation, select the close option from within the file menu. You can also click the icon on the toolbar.
Close can only execute if files are open. Otherwise the menu selection option appears faded (ghosted).
The close command detects if you alter the active file (the one that is displayed), but do not save it. In this case, it displays a message to give you the option to save it now. If you want to discard all changes and revert to the original file, click on the 'no' button in the message dialog box; otherwise click 'yes' or 'cancel'. Cancel aborts the close operation.