Constrain to Rectangle coordinates?

Hey All,
I’m doing a tutorial on using the startDrag function but have no idea how to get the coordinates for my rectangle.
How do you find the 4 points? I’ve tried using my mouse to pinpoint the location but that doesn’t work.

Here is the generic code:
myMovieClip.startDrag(false, left, right, top, bottom);

Many thanks for the help!