JSFiddle - React, Tailwind, and code Playground

HTML

<input type=text id=userWord>
<input type=button id=btnCheck value="Check word">

JavaScript

var button = document.getElementById("btnCheck");
var input = document.getElementById("userWord");
button.addEventListener("click", function(){ checkWord(input.value); });

function checkWord(input){

  var originalData = input;
  var a = [];

  for(var i = 0; i < input.length; ++i){
     a.push(input.charAt(i));
  }

  a.reverse();
  var reversedString = a.join('');

  var result =  (reversedString === originalData) ? true : false;
  alert(originalData  + " and " + reversedString + " are palindrones: " + result);
  
}