Returns the number of open images. Removes the specified window from the Window menu. Puts a checkmark in the Windows menu next to the specified window. Makes the specified image active. Returns the number of open images.
Returns null if no windows are open.
Adds the specified window to the Window menu. Removes the specified window from the Window menu. Puts a checkmark in the Windows menu next to the specified window. Closes all image windows. Activates the next window on the window list.