Tryit Editor v2.9

Edit This Code:
<!DOCTYPE html>
<html>
<head>
<script>

var myWindow;

function openWin() {
    myWindow = window.open("", "myWindow", "width=400, height=200");
}

function closeWin() {
    if (myWindow) {
        myWindow.close();
    }
}

function checkWin() {
    if (!myWindow) {
        document.getElementById("msg").innerHTML = "'myWindow' has never been opened!";
    } else {
        if (myWindow.closed) { 
            document.getElementById("msg").innerHTML = "'myWindow' has been closed!";
        } else {
            document.getElementById("msg").innerHTML = "'myWindow' has not been closed!";
        }
    }	
}

</script>
</head>
<body>

<button onclick="openWin()">Open "myWindow"</button>
<button onclick="closeWin()">Close "myWindow"</button>
<br><br>
<button onclick="checkWin()">Has "myWindow" been closed?</button>
<br><br>
<div id="msg"></div>

</body>
</html>