JSFiddle - React, Tailwind, and code Playground

HTML

<button>Hola</button>
<p></p>

JavaScript

var valor = 0,
    boton = document.getElementsByTagName("button")[0],
    parrafo = document.getElementsByTagName("p")[0];

boton.addEventListener("click", function(){
    parrafo.innerHTML = "Has realizado " + ++valor + " clics";
    if (valor % 5 == 0)
      alert("Bien");
}, false);