JSFiddle - React, Tailwind, and code Playground

by Glenn

HTML

<link rel="stylesheet" href="//maxcdn.bootstrapcdn.com/bootstrap/3.2.0/css/bootstrap.min.css">
<script src="//maxcdn.bootstrapcdn.com/bootstrap/3.2.0/js/bootstrap.min.js"></script>
<div class="row" id="multiple-prizes">
    <div class="col-sm-4" id="upload_prize_img">
        <div id="upload-logo sweep" class="upload-design-logo dropzone">
             <h3>Some upload button</h3>

        </div>
    </div>
    <div class="col-sm-8" id="upload_prize_form">
        <div>Name
            <input type="text" name="sweepstake-prize-name" id="sweepstake-prize-name" class="form-control"></input>
        </div>
        <div>Description
            <textarea name="sweepstake-prize-description" id="sweepstake-prize-description" class="form-control"></textarea>
        </div>
        <div>Amount
            <input type="number" name="sweepstale-prize-amount" id="sweepstake-prize-amount" class="form-control"></input>
        </div>
    </div>
</div>

CSS

#upload_prize_img {
    border: 1px solid red;
    width: 33%;
    float: left;
}
#upload_prize_form {
    border: 1px solid green;
    width: 66%;
    float: left;
}
#multiple_prizes {
    overflow: hidden;
}

JavaScript

var divh = document.getElementById('upload_prize_form').offsetHeight;
document.getElementById('upload_prize_img').style.height = divh + 'px';