JQuery POST only adding record to mysql once - php

Question

I'm using JQuery to call a php script which will add a record to the mySQL database.
This works fine for the first time I try to add something, but if I want to add more records to the database, it will not add anything. There are no errors in the console or php error log. It does not work if I refresh or reopen the page either.
jquery:
$(document).ready(function(){
$("#myForm").submit(function(){
var username = $("#username").val();
var password = $("#password").val();
var repassword = $("#repassword").val();
var email = $("#email").val();
var reemail = $("#reemail").val();
if(password != repassword)
{
alert("Passwords do not match");
return false;
}
else if(email != reemail)
{
alert("Emails do not match");
return false;
}
else {
$.post("signup_script.php",
{
username: username,
password: username,
email: email
});
}
});
});
php:
<?php
include_once('profile_Functions.php');
$username = $_POST['username'];
$password = $_POST['password'];
$email = $_POST['email'];
createUser($username,$password,$email);
?>
html:
<div class="body"></div>
<div class="grad"></div>
<div class="header">
<div>odd<span>job</span></div>
</div>
<br>
<div class="signup">
<script src='http://cdnjs.cloudflare.com/ajax/libs/jquery/2.1.3/jquery.min.js'></script>
<script type = "text/javascript" src="js/js_functions.js"></script>
<form id ="myForm" action ="" method = "post" >
<input type="text" placeholder="username" id ="username" required = "required" maxlength = "15"><br>
<input type ="email" placeholder = "email" id = "email" required = "required" maxlength = "50"><br>
<input type ="email" placeholder = "re-enter email" id = "reemail" required = "required" maxlength = "50"><br>
<input type="password" placeholder="password" id="password" required = "required" pattern = "(?=.*\d)(?=.*[A-Z]).{10,}"><br>
<input type="password" placeholder="re-enter password" id ="repassword" required = "required"><br>
<p class = "passwordreq">Password must:</p>
<ol class = "passwordreq">
<li>Have 10 characters</li>
<li>Have one number</li>
<li>Have one uppercase letter</li>
</ol>
<input type="submit" value="sign up" id ="submit">
<input type="button" value="go back" onclick="window.location='index.html'">
</form>
insert function:
function setup(){
extract($_GET);
extract($_POST);
extract($_SERVER);
$host="localhost";
$user="root";
$passwd="";
$connect=mysql_connect($host,$user,$passwd) or die("error connecting mysql server");
mysql_select_db('oddjob',$connect) or die("error accessing db");
}
function createUser($name, $pass, $email){
setup();
$hashed_password = password_hash($pass, PASSWORD_DEFAULT);
$sql = "insert into profiles (UserName, Password, Email) values ('$name', '$hashed_password', '$email'); ";
$res = mysql_query($sql);
}

Answer 1

I wonder if the solution is related to this question: https://stackoverflow.com/a/6143475/652519.
Can you add the error function to your post function? Like so:
$.post("signup_script.php",
{
username: username,
password: username,
email: email
})
.error(function() { alert("error"); });
Then we can see if there are errors that happen upon insert in the DB.

Answer 2

You should close your connection each time
mysql_close($connect)