<div id="overlay-box" class="overlayBox">
  <a class="closeBtn" onClick="closePop()">X</a>
  <button id="flipCard">Flip</button>
  <div class="content" ></div>
</div>

<script type="text/javascript">
    var front = document.getElementById("overlay-box")
    var  back_content = "
    <div class = 'overlayBox' style='top: 50.5px; left: 338px; display: block;'>
      <h2>Hello</h2>
      <a class = 'closeBtn' onClick = 'closePop()'>Y</a>
      <button id = 'closeCard'>Back</button>
      <div class = 'content'></div>
  </div>"

var  back

document.getElementById("flipCard").addEventListener('click',function(e){
    back = flippant.flip(front, back_content,'card')
    document.getElementById("closeCard").addEventListener('click',function(e){
        back = back.close();
    })
})