function changeCounter(diff) {
  if (state == states.start) {
    if (counter + diff > 0) {
      counter = counter + diff;
      showCounter(true);
    }
  }
}
// timer value (counter) can be changed in state start
timer value (counter) can be changed in state start
timer value ( counter ) can be changed in state start
function changeCounter(diff) {
  if (state == states.start) {
    if (counter + diff > 0) {
      counter = counter + diff;
      showCounter(true);
    }
  }
}
function changeCounter ( diff ) { if ( state == states . start ) { if ( counter + diff > 0 ) { counter = counter + diff ; showCounter ( true ) ; } } }
timer value (counter) can be changed in state start
timer value ( counter ) can be changed in state start