<html>
<head>
<title>Multiple Windows</title>
</head>
<body>
<button onclick="increment().then(c=>document.getElementById('count').innerText=`Count: ${c}`)">Increment</button>
<p id="count">Count: 0</p>
<button onclick="decrement().then(c=>document.getElementById('count').innerText=`Count: ${c}`)">Decrement</button>
</body>
</html>