problem with fillet

 From:  Janine4d
Hi there, first of all - I really love this app! It's very pretty looking and very user friendly, really fun to use and easy to learn. And hasn't crashed once, not bad. ;)

I'm not very experienced with nurbs modeling, so I might be doing something wrong. But I can't seem to add fillets to the selected curves (see image). I've attached the model too. Any ideas?