HyperNeWS requires a menu service that allows the instant showing of menus. 
This is achieved with the following routines.
Firstly only menubutton-events resulting from a ClassMenuCanvas canvas can
be used by the following routines. You must therefore subclass ClassMenuCanvas
and define the 'onmenu' method which is called when the menubutton is clicked in
the canvas (wether it has a menu or not). Note that tracking is not possible on
the menubutton.

subclasser routines of ClassMenuCanvas
--------------------------------------
/onmenu			% --
	The menu button was clicked in the canvas.

The 'onmenu' process can (it doesn't have to) show menus using the showmenu 
and showxymenu. 

menu utillities
---------------
/menuable		% -- boolean
	Returns true if the process can successfully do a showmenu or showxymenu.
	This is only possible if the process results from a ClassMenuCanvas and it
	has NOT shown a menu before.

/showmenu		% menu --
	Shows a menu at the location of the menu-button-click. The default choice
	of the menu will be alingned with the cursor.

/showxymenu		% menu x y --
	Shows a menu with its NothWest corner at the specified location 
	in the current coordinate system.

ClassHNMenu is a subclass of ClassMenu. It only specifies how the Notifier proc
is called. Choosing a menu item results in a Send to the appropriate target
(the target is the object which called the showmenu or showxymenu). It is NOT
required that you use ClassHNMenu.