<html >
<body>
<h2>JavaScript Confirm Box</h2>

<button onclick="myFunction()">Try it</button>

< p id="demo"></p>

<script >
function myFunction() {
var txt;
if (confirm("Press a button!") == true) {
txt = "You pressed OK!";
} else {
txt = "You pressed Cancel!";
}
document.getElementById("demo").innerHTML = txt;
}
</script >
< /body>
</html >