wgm

Hi I have recently acquired a 2000 echo. The audio unit in the car is a CD/Radio; Toyota model 31804. This is not the model shown in the owners manual. It shows H and M in white above the buttons for channels 1 and 2, shows 'set' above channel 3 and shows 'clock' above the AM/FM button. I was trying to reset the clock display and pressing combinations of these buttons, both with the radio on and with the radio off. Now the clock display seems to have disappeared and the display just shows the radio station number. Does anyone know (a) how to get the clock display back and (b) how to adjust the clock? Thanks in advance for any help or suggestions. Bill