function initOpenNewWindow() {
  var popupEvent = function(event) {
    window.open(this.href).focus();
    event.preventDefault();
    event.stopPropagation();
  }
  $("a[rel='external']").each(function(i) {
      $(this).click(popupEvent);
      $(this).keypress(popupEvent);
  });
}

$(document).ready(initOpenNewWindow);