index.html
<!DOCTYPE html>
<html>
<body>
<p>Count numbers: <output id="result"></output></p>
<button onclick="startWorker()">Start Worker</button>
<button onclick="stopWorker()">Stop Worker</button>
<br /><br />
<script>
var w = null;
function startWorker(){
if(typeof(Worker)!=="undefined"){
if(w==null){
w=new Worker("worker.js");
}
w.onmessage = function (event) {
document.getElementById("result").innerHTML=event.data;
};
}
else{
document.getElementById("result").innerHTML="Sorry, your browser does not support Web Workers...";
}
}
function stopWorker(){
if(w==null){
return;
}
w.terminate();
w = null;
}
</script>
</body>
</html>worker.js
var i=0;
function timedCount(){
i=i+1;
postMessage(i);
setTimeout("timedCount()",500);
}
timedCount();