digital clock..pls help me...

i need help in creating a circuit diagram for my digital clock...it was assigned to me by my professor...he said that the digital clock should have 3 tact switches, 1st one is for set and reset of the clock, 2nd switch will be for choosing what to set, hour or minute, then the third will be for the time format, 12hr or 24hr format..pls give me ideas..or if you know someone who has a diagram for this, pls send me the link...tnxxx...

i would be using a pic16f84a ic for this...tnx..

What is your readout?

4 7-segment display...

There are already clock projects on the web using this chip and have 3 buttons and provide the .asm code.