JSFiddle - React, Tailwind, and code Playground

HTML

<form method="post" action="somepage">
    <textarea name="content" style="width:50%"></textarea>
    <p>
    <input type="submit" value="Submit">
</form>

JavaScript

var input = document.getElementsByTagName("input")[0];

input.addEventListener("click", 
                       function (event) {
                           event.preventDefault();
                           var textBox = document.getElementsByName("content")[0];
                           alert(textBox.value);
                       }, 
                       false);