How do I script for the effect of menu item "Reshape Graphic"

[Jim Hurley]

I have a button with the following handler:

on mouseUp
   set the markerdrawn of grc 1 to true
end mouseUp

where graphic 1 is a polygon.

And a second button with the handler:

on mouseUp
   set the markerdrawn of grc 1 to false
end mouseUp

These two button have no effect on the polygon until I select the 
polygon and then call "Reshape Graphic" from the Object menu. From 
this point on the two buttons then show and hide the markers.

How can I script for whatever "Reshape graphic" does?

Also, I haven't a clue what those little "Points" are below the "Draw 
shape at vertices" box in the Inspector. Points like: -3,1 and -2,1 
etc. I'll bet they do something interesting. Where do I find these in 
the docs?

Jim