This function 'lends' the menus of one window to another. This makes the menu events (eg. menu button press) take place in another window's menu (ie. the other window's strip and screen). This function is used to unify two windows on different attached screens. (Eg. a painting program with an attached palette screen can open the menu on the main screen if the menu button is pressed on the palette screen.
INPUTS
fromwindow
This window's menu events will go to another window.
towindow
This is the window that will react on the menu actions of the other window. If NULL 'lending' will be turned off.