<!DOCTYPE html>
<html>
<body>
<p>Click the button to open a new window, and assure that the new window does NOT GET focus (send the new window to the background).</p>
<button onclick="myFunction()">Try it</button>
<script>
function myFunction() {
var myWindow = window.open("", "", "width=200, height=100");
myWindow.document.write("<p>A new window!</p>");
myWindow.blur();
}
</script>
</body>
</html>