520 ASK MOUSE X%,Y%,B% : IF B% = 0 THEN LC = 0 : GOTO 520 ELSE IF X% < 74 OR X% > 80 THEN 520
530 IF Y% > 56 AND Y% < 64 THEN IF LC = 1 THEN 520 ELSE FL = - (FL = 0) : PENA FL : BOX (73,56;81,64),1 : LC = 1 : GOTO 520
540 Z = INT (Y%/8) : IF Z = 11 THEN 595 ELSE IF Z = 8 THEN 550 ELSE IF Z = 9 THEN 3000 ELSE IF Z = 10 THEN 4000 ELSE IF Z > 5 THEN 520 ELSE MD = Z : GOSUB 590 : GOTO 520