将Google地址解析器发送到mysql插入0

I'm using google geocoder to get latitude and longitude on an address. I can see that in my JS code the numbers are returned ok. but after sending them to my PHP file and inserting into the Mysql DB, I get only zeros. The column in the DB is double. When inserting a number manually instead of the geocoder results, it works fine.

Any ideas? Thanks!

This is the JS:

  var geocoder = new google.maps.Geocoder();
  geocoder.geocode( { 'address': address.val()}, function(results, status) {
    if (status == google.maps.GeocoderStatus.OK) {
      if (isEmptyInputValidation(city) || isEmptyInputValidation(street) || isEmptyInputValidation(addressNumber)){
        formValid = false;
        redInputError(address);
      }
      else{
        latitude  = (results[0].geometry.location).lat();
        longitude = (results[0].geometry.location).lng();
      }
    }
    else {
      alert("Geocode was not successful for the following reason: " + status);
      redInputError(address);
    }
  });

  if(formValid) {
    var email = getItemFromLocalStorage('email');
    var password = getItemFromLocalStorage('password');

    latitude = (results[0].geometry.location).lat();
    longitude = 34.885372;

    $.ajax({
      url: "http://gsbeta.hol.es/php/register-sitter.php",
      type: 'POST',
      data: $("#form_sitter_registration").serialize() + '&email=' + email + '&password=' + password
                                                       + '&latitude=' + latitude + '&longitude=' + longitude,
      success: function(data) {
        setCookie("userId", data);
        setCookie("firstName", firstName);
        setCookie("lastName", lastName);
        setCookie("email", email);
        setCookie("isParent",0);
        //window.location.href = 'search_sitter.html';
      },
      error: function(error) {
        alert('error');
       }
    })
  }
});

This is the php:

<?php
  header("Access-Control-Allow-Origin: *");

  include 'dbconfig.php';

  $email          = $_POST['email'];
  $password       = md5($_POST['password']);
  $first_name     = $_POST['first_name'];
  $last_name      = $_POST['last_name'];
  $phone          = $_POST['phone'];
  $city           = $_POST['city'];
  $street         = $_POST['street'];
  $address_number = $_POST['address_number'];
  $latitude       = $_POST['latitude'];
  $longitude      = $_POST['longitude'];
  $info           = $_POST['info'];

  $insert = $conn->query("INSERT INTO users (email, password, first_name, last_name, phone, city, street, address_number, info, is_parent, latitude, longitude)
                          VALUES ('$email', '$password', '$first_name', '$last_name', '$phone', '$city', '$street', '$address_number', '$info', 0, '$latitude', '$longitude');");

  $sitter_id = mysqli_insert_id($conn);
  $birthday = date ("Y-m-d H:i:s",strtotime($_POST['month']."/".$_POST['day']."/".$_POST['year']));
  $cost_per_hour =  $_POST['cost_per_hour'];
  $is_mobile =  $_POST['is_mobile'];
  $youngest_age =  $_POST['youngest_age'];
  $oldest_age =  $_POST['oldest_age'];

  $insert = $conn->query ("INSERT INTO sitter (id, birthday, cost_per_hour, is_mobile, youngest_age, oldest_age) VALUES ('$sitter_id', '$birthday', '$cost_per_hour', '$is_mobile', '$youngest_age', '$oldest_age');");

  $conn->close();
  echo($sitter_id);
?>