When I right click a repeating event entry on my desktop Thunderbird calendar, I get the Delete Repeating Event dialog window which has two options and a Cancel button (refer to attachment). This window should have an OK button, as it is not clear that by clicking one of the two options, that selection is chosen and the window is automatically closed. As a user I should be able to toggle between the two selections and then press OK to confirm my selection of the highlighted option.
