Here's a summary of commands for the documentation:

ClearOverlay ()
	Clears the overlay.

newLine = Overlay.MakeLine (obj1, obj2)
newLine = Overlay.MakeLine (x,y, obj)
newLine = Overlay.MakeLine (obj, x,y)
newLine = Overlay.MakeLine (x1,y1,x2,y2)
	Draw a line between points and/or objects on the overlay.
newLine.SetColor(self, *args)
	Set the line's color.
newLine.SetWidth(w)
	Set the line's width.
newLine.Destroy()
	Destroy the line.

myText = Overlay.MakeText (s, xpos,ypos)
	Draw text string s at position xpos,ypos on the overlay.
myText.SetColor(color)
	Set the text's color.
myText.SetText(self, s)
	Change the text string.
myText.SetPosition(x,y)
	Change the text position.
myText.Destroy()
	Destroy the text object.


newFilledRectangle = Overlay.MakeFilledRectangle (a,b,c,d)
	Draw a filled rectangle with corners at (a,b) and (c,d).
newFilledRectangle.SetColor(color)
	Change the rectangle's outline color.
newFilledRectangle.SetFillColor(color)
	Change the rectangle's fill color.
newFilledRectangle.SetCoordinates(a,b,c,d)
	Change the rectangle's coordinates.
newFilledRectangle.Destroy()
	Destroy the rectangle.


newRectangle = Overlay.MakeFilledRectangle (a,b,c,d)
	Draw an empty rectangle with corners at (a,b) and (c,d).
newRectangle.SetColor(color)
	Change the rectangle's color.
newRectangle.SetCoordinates(a,b,c,d)
	Change the rectangle's coordinates.
newRectangle.Destroy()
	Destroy the rectangle.

newCircle = Overlay.MakeCircle ()
	Draw an filled circle with center at (x,y) and radius r.
newCircle.SetColor(color)
	Change the circle's outline color.
newCircle.SetFillColor(color)
	Change the circle's fill color.
newCircle.Destroy()
	Destroy the circle.

newButton = Overlay.MakeButton (ButtonText, xpos, ypos, function):
	Create a button labeled ButtonText at position xpos,ypos.
	Call function f when the button is clicked.
newButton.Destroy()
	Destroy the button.