elevations

Hey,
I am trying to get my head round how elevations work and need a bit of help if you can:
1) What dimention is the number of the elevation in?
2)Double clickign selects a whole portion of track, can a choose a section of track set this at the right height and then tell trax where I would like the track to start and end sloping to that elevated section?
3) Can you elevate points/switches?
4) How can I elevate a whole table in order to have a portion of track above another portion?

Thanks for you help,
Matt