                 ------- CURVE (Function Key) -------


--  This function key will draw an arc (curve) through 3 points.

--  This requires pressing the function key twice:
    --  once to establish the mid pt of the curve, and
    --  once to establish the end pt of the curve.

 
                   *** EXAMPLE ***
 
--  If you have two flashing "+" on the screen, you may press this
    function key for the first time.  
    If you have only one flashing "+", move the cursor (making two "+") where
    you want the mid pt of the curve to be and then press the function key.

    NOTE  Nothing will be drawn just yet. 

    NOTE  By pressing the function key for the first time, you have 
          defined where the middle point of the curve is.

          The beginning pt of the curve is where the from pt is 
          (the other flashing "+").

--  Move the cursor to where you want the end pt of the curve to be
    and press the function key again.

    NOTE  This should draw an arc (curve) from where the from pt was
          through where you defined the mid pt and ending at the last
          point defined.

    NOTE  There will now be only one flashing "+" because both the new
          from pt and the cursor are at the same location.
OTE  There will now be only one flashing "+" because both the new
          from pt and the cursor are at the same l