Hi. I'm trying to model an if / else statement in a sequence diagram using an alt combined fragment and a number of interaction operands.

Initially I drag a combined fragment around the relevant sequence. However when I try and change the fragment's interaction operator to Alternative, it doesn't change on the diagram (it still shows seq).

Also when I try dragging interaction operands into the combined fragment, they do not appear, even though the cursor indicates it is valid to do so.

Can anyone please advise on how to do this as the MyEclipse UML2 tutorial is still non-existent?

Many thanks in advance.

It seems also that fragments are not actually added to the model so when I close it and reopen I get lots of "unresolved" errors on the diagram.

Am I using this completely wrong or perhaps has something gone wrong with my installation? No one else seems to be complaining which would suggest it's working for other people.