I have lost my creda concept halogen manual. As you will note the cooker was bought around 1993 but is in good working order. I cannot remember how to alter the time !! I have tried lots of combinations of touching and holding the buttons but none seems to work and it keeps reverting to the wrong time!! (I always had to read the instructions as I couldn't remember the correct way!! ) The auto or cook symbol keeps coming on when I try various methods. Can you help please?