Hey thank you so much !!!! I'm italian and my english is very bad but i understand perfectly what i have to do for my saddle.
Thank you again

I follow the instruction there is here: http://www.jawa9000.com/Technical/workshop/nurbs-surfaces.htm

Thanks for answer!
I select the curves green and white, and then i select the middle and right curves.
I think surface will create follow the middle and the right curves, starting from the green...

But nobody knows the Birail2 comand???

Hi to all.
I've drawn some curves for make a bike saddle, when i click "Birail 2" nothing happens....

there is the image http://www.briscola5star.it/pages/service/box/sellaWorking.png