JSFiddle - React, Tailwind, and code Playground

HTML

<div id="loading">
  <img id="loading-image" src="http://cdn.nirmaltv.com/images/generatorphp-thumb.gif" alt="Loading..." />
</div>
<div id="txt"><h2>Let AJAX change this text</h2></div>
<button>Change Content</button>

CSS

#loading {
  width: 100%;
  height: 100%;
  top: 0px;
  left: 0px;
  position: fixed;
  display: block;
  opacity: 0.7;
  background-color: #fff;
  z-index: 99;
  text-align: center;
}

#loading-image {
  position: absolute;
  top: 100px;
  left: 240px;
  z-index: 100;
}

JavaScript

$(window).load(function() {
	 alert("hi");
    $('#loading').hide();
  });