$(document.body).on('keyup', function(event) {
  var linkClass;
  switch(event.which) {
    case 37: // left arrow
    linkClass = '.previous-guide';
    break;
    case 39: // right arrow
    linkClass = '.next-guide';
    break;
    default:
    return;
  }
  window.location.assign && window.location.assign($(linkClass).attr('href'));
});