example

index.html

<table>
<tr><td id="00"></td>   <td id="01">   </td><td id="02"></td></tr>
<tr><td id="10"></td><td id="11"></td><td id="12"></td></tr>
<tr><td id="20"></td><td id="21"></td><td id="22"></td></tr>
</table>
<style>
table, th, td {
   border: 1px solid black;
}
td {
  width: 50px;
  height: 50px;
}
</style>
<script>
board = [[0,0,0],[0,0,0],[0,0,0]]
turn = false
elems = document.getElementsByTagName('td')
for(i = 0; i < elems.length; i++){
  elem = elems[i]
  elem.onclick = selectSpot
}
function selectSpot() {
  id = this.id
  if(empty(id)){
    spot(id, player())
    advanceTurn()
  }
}
function advanceTurn() {
  turn = !turn
}
function player() {
  if(turn)
    return 1
  else
    return 2
}
function empty(id) {
  return spot(id) == 0
}
function spot(id, value) {
  x = id[0]
  y = id[1]
  if(value){
    board[x][y] = value
    placeMark(id)
  } else {
    return board[x][y]
  }
}
function placeMark(id) {
  color = turn ? 'blue' : 'red'
  document.getElementById(id).style.backgroundColor = color
}
</script>