Project help

well, my project is for a random head/tail generator and using an i-matrix display i need to alternate between a T and an H and then have a button to stop the cycle and display either symbol.
To do this i have made up a circuit invlving a clock, a counter and some logic so each column will get a pulse one after the other. i can a make a T or an H but i dont know how to get them to alternate or how to connect in a button to stop them, can anyone help me ?

Use a JK Flip Flop and connect Vcc to the J and K inputs via a 10k resistor. The push button is connected from the J & K to ground and the oscillator to the clock input. The Q output will change from High to Low at half the oscillator frequency. It will stop at H or L at random when the button is pressed.

The reason for the FF is to create a 50/50 mark to space ratio so the probability of a Head or Tail is equal. (the mark to space ratio of the oscillator is unlikely to be exactly 50/50)

Len