´<script>
$(document).on("click", "#login_user", function(e) {
e.preventDefault();
var formData = $('#login_form').serialize();
var email = $("#email").val();
var password = $("#password").val();
if(email === ''){
alert("Preencha o campo email!");
}else
if(password === ''){
alert("Preencha o campo password!");
}else{
$.ajax({
type: "POST",
url: "https://www.sabeonde.pt/api/api_login.php",
data: formData,
cache: false,
}).done(function(msg) {
alert(msg.error);
}).fail(function(data) {
alert(msg.error);