Once MIDI files were reliably playing in the browser (see the previous post), the next thing I wanted was to have them play in little popup windows, instead of making a blank new page and playing there. Having to hit the browser's "Back button" after playing any MIDI was not acceptable.
The first way I did this was to put the Javascript code to make the popup window inside the link (with an onclick attribute). The problem with that method is that the link is completely broken when Javascript is not supported. Clearly a new page to play the file is the best option when Javascript is not supported.
So, the question is, how can one get a popup when Javascript is supported, but have the link still go to a new page and load the file when it is not?