$(document).ready(function(){
  $("#enter_number").submit(function(e) {
    e.preventDefault();
    initiateCall();
  });
});

function initiateCall() {
  $.post("call.php", { phone_number : $("#phone_number").val() },
    function(data) { showCodeForm(data.verification_code); }, "json");
  checkStatus();
}

function showCodeForm(code) {
  $("#verification_code").text(code);
  $("#verify_code").fadeIn();
  $("#enter_number").fadeOut();
}