Confused about screen coordinates vs local coordinates, .x vs .xOrigin, etc.

The illustration of what I want to do: http://skitch.com/tokyodan/dhsjh/skitched-20101022-202404

I’m trying to make a dual preferences screen that slides on to the main iPhone screen from the right.
The dual preferences screen (main group) is a 640 pixel-wide group that contains prefs1 group and prefs2 group
prefs1 group and prefs2 group each contain various buttons, text boxes and an image that is 320 pixels wide.
prefs2 group left edge should touch the right edge of prefs1 group so that they are side by side. (in main group prefs1 is at x=0, and prefs2 is at x=320)

I want to be able to slide in main group so that the pref1 group’s image is on the iPhone screen. this would be a transition.to with x = -320.

Then a 2nd transition.to with x = -320 should slide pref2 group’s image on the iPhone screen, with pref1 group’s image going off the left side of the iPhone screen.

  1. What screen (or local) coordinates should I use to do this?
  2. And should I use object.x or object.xOrigin to do this?
  3. Also how would I set button1 x position and button2 x position?

I wish there were some detailed examples about such things. [import]uid: 295 topic_id: 3006 reply_id: 303006[/import]