<!DOCTYPE html>
<html>
<head>
<script>
function myFunction() {
var myWindow = window.open("", "myWin", "left=700, top=350, width=200, height=100");
var winLeft = myWindow.screenLeft ? myWindow.screenLeft : myWindow.screenX;
var winTop = myWindow.screenTop ? myWindow.screenTop : myWindow.screenY;
myWindow.document.write("<p>This is 'myWin'");
myWindow.document.write("<br>Horizontal: " + winLeft);
myWindow.document.write("<br>Vertical: " + winTop + "</p>");
}
</script>
</head>
<body>
<p>Click the button to create a new window and get the horizontal and vertical coordinates of the new window relative to the screen.</p>
<button onclick="myFunction()">Open "myWin"</button>
<p id="demo"></p>
</body>
</html>