How: let the user resize components with the mouse?

I have some questions on some fancier kinds of tasks using the mouse.

Let's say I have two dbgrids one above the other.  I want to have the
components do as much of any work as they can, via the Align property
I should think (top, left, client, etc).  I want these grids to do two

- size themselves in "reasonable" ways as the form is resized;
- grow and shrink as the other does the opposite (shrinks/grows).

1. What are the best align settings for the two grids?  My guess is
top and client, but that breaks if you add a third component between

2. What is the best strategy to let the user size the height of these
two grids in ushc a way that when one grows, the other shrinks?  I've
played with putting a very short (3 pixels) panel in between them, and
assume drag/drop will be involved.  I thought I'd watch the mouse's v.
position but it wasn't clear to me which event handler of the control
would be best.  Some example code would be most helpful just now--I'm
not even sure if this is the right approach to take.

Perhaps someone could recommend a book that's good at describing this
facet of form manipulation.

Thanks in advance.
Frank Burleigh 812-333-7082 (h); 812-855-9170 (o); 812-855-0555 (fax)
School of Law 254, Indiana University, Bloomington, IN  47405
Internet or CIS 72730,1017 (rare visits)