problems with Logic Express export as MIDI file

In Logic express, I want to export my file as MIDI and despite having selected tracks in various ways, the dialogue box tells me that I need to "select a MIDI region" before exporting as a MIDI file. I'm beginning to think that what I thought of as a MIDI region is not what Logic Express thinks is a MIDI file. The Logic Express help has been no help at all so I'm hoping that someone out there can do what "help" cannot.

Thanks!