JSFiddle - React, Tailwind, and code Playground

HTML

<form id="basic" name="basic">

<label><input name="formelement" type="radio" value="yes" /> Yes   </label>
<label><input name="formelement" type="radio" value="no" /> No </label>

<div id="yes" style="display: none;">
This is the div that displays that shows when 'Yes' is selected.
</div>

<div id="no" style="display: none;">
This is the div that displays that shows when 'No' is selected.
</div>

</form>

JavaScript

window.onload=function(){
  var el1 = document.getElementsByName('formelement')[0];
  var el2 = document.getElementsByName('formelement')[1];  
  el1.onchange=function(){
      var show=el1.value;
      var hide=el2.value;
      document.getElementById(show).style.display='block';
      document.getElementById(hide).style.display='none';
  }
  el2.onchange=function(){
      var show=el2.value;
      var hide=el1.value;
      document.getElementById(show).style.display='block';
      document.getElementById(hide).style.display='none';
  }  
}