function imagePopup (link) {
  var popupWindow = window.open (
      '',
      'Viewer',
      'width=0,height=0,location=no,resizable=no,scrollbars=no,status=no'
    );
  var popupBody = popupWindow.document.body;
  popupBody.style.padding = '0';
  popupBody.style.margin = '0';
  var image = popupWindow.document.createElement ('img');
  image.style.margin = '0';
  image.onload =
    function() {
      popupWindow.resizeTo (image.clientWidth, image.clientHeight);
    };
  if (popupBody.firstChild) popupBody.removeChild (popupBody.firstChild);
  popupBody.appendChild (image);
  image.setAttribute ('src', link.href);
  popupWindow.focus();
  return false;
}