function show_phone(bus, fn) {
  // create cookie
  // display all phone details
  // send ajax request
  createCookie('disphone'+bus, '1', 1);
  $("#phno"+bus).show();
  $.ajax({
    url: "/"+fn+"/register_phone_click/",
    type: "GET"
  });
  $("#ph_"+bus).hide();
}

function hide_phone(bus) {
  // see if phone has already been accessed (cookies)
  // otherwise hide (graceful deg as phone numbers are show first, hide js second)
  if(readCookie('disphone'+bus)==null) {
    $("#phno"+bus).hide();
    $("#ph_"+bus).show();
  } else {
    $("#ph_"+bus).hide();
  }
}