JSFiddle - React, Tailwind, and code Playground

HTML

<div id="mydivhide1">1111</div>
<div id="mydivhide2">2222</div>

<div id="form_container">
    <form id="form_710370"  target="my_iframe" method="post" action="/">
        <input id="Website" name="url1" type="text" value=""/> 
        <input id="saveForm" type="submit" name="submit" value="submit" />
    </form> 
</div>

<div id="frameWrap">
<img id="loader1" src="http://www.fillmurray.com/200/300" alt="loading gif"/>  
    <iframe id="iframe1" name="my_iframe" src="/" > </iframe>
    </div>

CSS

#mydivhide1 {display:none;}
#mydivhide2 {display:none;}

JavaScript

$(document).ready(function () {
    $('#iframe1').on('load', function () {
        $('#loader1').hide();
        $('#form_container').show();
        $('#mydivhide1, #mydivhide2').hide();
    });
    $('#form_710370').submit(function(e){
        $('#loader1').show();
        $('#form_container').hide();
        $('#mydivhide1, #mydivhide2').show();
        return true;
    });
});