trigger an Unbounce lightbox on scroll

lb-on-scroll.html

<script>
/*
Unbounce Community :: Tips & Scripts :: Open Lightbox on Scroll 
TS:0002-04-085
***********************
Do not remove this section. It helps our team track useage of external workarounds.
*/
(function() {  
  // lightbox button ID
  var btn = $("#lp-pom-button-31");
  
  // amount of scroll before opening lightbox
  var scroll = 474;
      
  var i = true;
  $(window).scroll(function () {
    if ($(this).scrollTop() > scroll && i == true) {
      $(btn)[0].click();
      i = false;
    }
  });
})();  
</script>