Thank you for your replys and yes maybe not a daft question but could be complicated.
I would have thought that emirates were only interested in selling tickets and when you fly back was not a issue with them. lots of people might buy a return ticket from A to B and have plans on going from B to C and then C to D touring around the world using different airlines.

Reading the replies on nesting tickets , it shows that it does happen and what can a airline do if your found to be using the nesting System?? Ban you for life

Malc