anchor.diff:  
   var seats, rows;
   var canvas;
  +const SEAT_SIZE = 20;
  +const SEAT_GAP = 5;
   
   function renderSeatmap(canvas){
     //Render base canvas
  
positive.code:     success: function(data){
        rows = data.rows;
        renderSeatmap(canvas);
        console.log("updateseat done");
      }
    });
  }
  
negative.code:   for(i = 0; i < rows.length; i++){
      for(j = 0; j < rows[i].seats.length; j++){
        ctx.beginPath();
        coords = getViewCoord(i, j);
        ctx.rect(coords.x, coords.y, SEAT_SIZE, SEAT_SIZE);
        if(rows[i].seats[j].state == "available"){
          ctx.fillStyle = 'green';
        }else{
  