JSFiddle - React, Tailwind, and code Playground

HTML

<script src="http://code.jquery.com/jquery-1.9.1.js"></script>
 <input id="email" name="email" class="email" type="text" />
<br>
<br>
<div id="Button" style="height:100px; width: 150px; background-color: #000;">
    </div>

JavaScript

$( "input" ).change(function() {

    if ($('#email').val().indexOf('@' && '.') >= 0) {
       $('#email').val('Yes! It contains an "@" en . symbol!');
    } else { 
        $('#email').val('No :( No "@" symbol');
    }

});