JSFiddle - React, Tailwind, and code Playground

HTML

<body onload="setup()">

<input type="button" onclick="if (!confirm('Please, answer No')) { return false; }" value="Click me!">

<div id="testDiv" style="display:none"> If you answered No, you shouldn't be seeing this! </div>
</body>

JavaScript

function setup() {
    document.getElementsByTagName('body')[0].onclick = clickFunc;
}
function clickFunc(eventData) {
    var clickedElement = (window.event) ? event.srcElement : eventData.target;
    
    console.log('isDefaultPrevented: ' + (window.event||eventData).isDefaultPrevented);
    
    if (!((window.event||eventData).isDefaultPrevented == false)){
        document.getElementById('testDiv').style.display = "block";
    }
}