When some of the toolbar buttons or context menu items are clicked, modal dialogs/windows will appear.

A modal dialog will take total control and thus not allow the user to access the parent/main window. When a modal dialog appears, you must always close it before continuing work in the parent/main window. The following screenshot shows one of the modal dialogs.

The "Insert special character" dialog.

Please note that Mozilla based browsers may not support modal dialogs in the correct way. You might be able to work with the parent/main window even if a dialog is being displayed. This should never be done! Whenever a modal dialog appears it must be closed before the parent/main window is used.