function buy_now(seminar_id)
{
  open(webroot + 'education/seminar_signup/' + seminar_id,
       'seminar_signup',
       'width=500,height=400');
}

function waiting_list(seminar_id)
{
  open(webroot + 'education/seminar_wait_list/' + seminar_id,
       'seminar_signup',
       'width=500,height=350');
}