Implementing computer player

This is the click function. I've inserted a computer player and need it to replicate what the users click does. It is a connect four game.

 click: function(ev) {
  var component = this;
  if(component.get('playing') && !component.get('winner')) {
    if(ev.target.tagName.toLowerCase() == 'canvas' && ev.offsetX < 360 && ev.offsetY < 360) {
        var x = Math.floor((ev.offsetX) / 51.5);
        var y = Math.floor((ev.offsetY));
        var state = component.get('state');
        var gridHeight = state[0].length;

        for(y = 1; y < gridHeight; y++ ) {
          if(state[x][y]) {
          //this cell is occupied, so choose the cell above y
          break;
        }
    }

      y = y - 1;

This is what makes the users counter go up one when the desired spot is already occupied

        if (!state[x][y]) {
          var move_count = component.get('moves')['x'];
          var marker = component.get('markers')['x'][move_count];
          state[x][y] = 'x';
          marker.visible = true;

          marker.x = 25 + x * 51.5;
          marker.y = 20 + y * 60;
          component.check_winner();
          component.get('moves')['x'] = move_count + 1;
          setTimeout(function() {
            if(!component.get('winner')&& !component.get('draw')) {
              var move = computer_move(state);
              move_count = component.get('moves')['o'];
              state[move.x][move.y] = 'o';
              marker = component.get('markers')['o'][move_count];
              marker.visible = true;
              marker.x = 25 + move.x * 51.5;
              marker.y = 20 + move.y * 60 ;
              component.get('moves')['o']= move_count + 1;
              component.get ('stage').update();
              component.check_winner();
            }
          }, 200);
        }
     console.log(state);
  }

} },

I need the computer to be able to drop the counters in the same fashion as the user