game.html

<html>
<head>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.3/jquery.min.js"></script>

<script src="game.js"></script>

<style>
	body {
		margin: 0 0 0 0;
		padding: 0 0 0 0;
	}

	#board {
		width: 100%;
	}

	.place {
		float: left;
		width: 40px;
		height: 40px;
		cursor: pointer;
		text-align: center;
		vertical-align: middle;
		background: #eee;
		line-height: 40px;
		font-size: 20px;
		border-right: 1px solid #000;
		border-bottom: 1px solid #000;
		-moz-user-select: none; 
        -khtml-user-select: none; 
        -webkit-user-select: none; 
        -o-user-select: none; 
        user-select: none;
	}
</style>


</head>

<body>
	<div id="whichPlayer">Player A</div>
	<input id="n" type="text" /><button id="setN">Zet Bordlengte</button> <button id="undo" >Undo</button> <br><br>
	<div id="board"></div>
</body>
</html>