Code Run - Live Demo

<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">
<title>Start/Stop Web Worker in HTML5</title>
<script>
    // Set up global variable
    var worker;
    
    function startWorker() {
        // Initialize web worker
        worker = new Worker("examples/resources/worker.js");
        
        // Update result, when we get a message from worker
        worker.onmessage = function (event) {
            document.getElementById("result").innerHTML = event.data;
        };
        
        // Tell worker to get started
        worker.postMessage("start");
    }
    
    function update(event) {
        // Update the page with current message from worker
        document.getElementById("result").innerHTML = event.data;
    }
    
    function stopWorker() {
        // Stop the worker
        worker.terminate();
    }
</script>
</head>
<body>
    <h1>Web Worker Demo page</h1>
    <button onclick="startWorker();" type="button">Begin web worker</button>
    <button type="button" onclick="stopWorker();">End web worker</button>
    <div id="result">
        
    </div>
</body>
</html>