0)  Description:
    A number is displayed at the center of client area.
    Left click displays the dialog allowing to change the number.
    Right click displays a dialog allowing to specify the permissible
    range of displayed numbers (if the dialog is already visible it is closed).
    Note: OK accepts the range. Cancel restores it. Close closes the dialog.
    
1)  Project consists of *.cpp & !.rc files.
2)  Use AppStudio to create dialogs.
    Use ClassWizard to create dialog classes 
    (specify ClassType as CDialog).
3)  Note how OK and Cancel are overriden.
