I have an Excel javascript add-in that includes some cell right-click actions, which can therefore be done when the add-in’s task pane is not showing.

One of the actions should launch a pop-up dialog. But when running on the web, that dialog could be blocked by popup-blockers.

How/where can I show a message to the user in this case, asking them to allow the popup?

The right-click command runs in its own hidden browser window, so I can’t show anything in the window, nor use window.alert() etc to show a message.

In the right-click situation, the task pane is likely not showing, so I can’t pop up a message there (even though that’s where Excel shows the ‘promptBeforeOpen’ box).

The Excel object model doesn’t seem to expose any message / status / alert options.

So how can I show a message, asking the user to allow popups for my domain?