<!DOCTYPE html>
<html>
<body>

<p>Click the button to open a new window and close the window after three seconds (3000 milliseconds)</p>

<button onclick="openWin()">Open "myWindow"</button>

<script>
function openWin() {
    var myWindow = window.open("", "myWindow", "width=200, height=100");
    myWindow.document.write("<p>This is 'myWindow'</p>");
    setTimeout(function(){ myWindow.close() }, 3000);
}

</script>

</body>
</html>