JSFiddle - React, Tailwind, and code Playground

HTML

<div>
    <input type="text" id="input" value="Mozilla" /> 
    <button onclick="func()">Test</button> 
    <span id="result"></span>
</div>

JavaScript

function func(i) {
    var regex = /^(?!Mozilla)/;
    var input = document.getElementById('input').value;
    var result = regex.test(input);
    document.getElementById('result').innerHTML = 'Result: ' + result; 
}