JSFiddle - React, Tailwind, and code Playground

HTML

<form method="post" name="form" onsubmit="validate();return false"> Name :
  <input type="text" id="name" name="name" />
  <div id="errorBox"> </div>
  <br>
  <input type="submit" name="submit" value="submit" />
  <input type="Reset" name="Reset">
</form>

JavaScript

function validate() {
  var a = document.form.name.value;

  if (!a) {
    document.getElementById("errorBox").innerHTML = "*Please fill required";
  } else {
    document.getElementById("errorBox").innerHTML = "";
  }
}