task main(){
  while(button is not pressed){  //wait for button to be pressed.
    Wait1MSec(1);
  }

  ClearTimer(T1); //set timer to zero

  while(button is not pressed){  //wait for button to be pressed again
    Wait1MSec(1);
  }
 
  int time = time1[T1]; //time = the number of milliseconds that have passed.
}