PROCEDURE define_new_keys

        CTRL4  :=  KEY_NAME ( ASCII ( 28 ) ) ;
        CTRL5  :=  KEY_NAME ( ASCII ( 29 ) ) ;
        CTRL6  :=  KEY_NAME ( ASCII ( 30 ) ) ;
        CTRL7  :=  KEY_NAME ( ASCII ( 31 ) ) ;
        DEFINE_KEY ( "MESSAGE ( 'CONTROL-4' )" , CTRL4 ) ;
        DEFINE_KEY ( "MESSAGE ( 'CONTROL-5' )" , CTRL5 ) ;
        DEFINE_KEY ( "MESSAGE ( 'CONTROL-6' )" , CTRL6 ) ;
        DEFINE_KEY ( "MESSAGE ( 'CONTROL-7' )" , CTRL7 ) ;

ENDPROCEDURE ;