ttimsmith/theboldreport.net

function windowPopup(url, width, height) {
  // Calculate the position of the popup so
  // it’s centered on the screen.
  var left = (screen.width / 2) - (width / 2),
      top = (screen.height / 2) - (height / 2);

  window.open(
    url,
    "",
    "menubar=no,toolbar=no,resizable=yes,scrollbars=yes,width=" + width + ",height=" + height + ",top=" + top + ",left=" + left
  );
}

$(".js-social-share").on("click", function(e) {
  e.preventDefault();

  windowPopup($(this).attr("href"), 500, 300);
});