Center Images Vertically in JavaScript

centerImagesVertically.js

jQuery(function () {

  var imageHeight, wrapperHeight, overlap, imageContainer = $(".center_vertically");

  function centerImagesVertically() {
    imageHeight = imageContainer.find("img").height();
    wrapperHeight = imageContainer.height();
    overlap = (wrapperHeight - imageHeight) / 2;
    imageContainer.find("img").css("margin-top", overlap);
  }

});