function createUID($table, $field)
{
do {
$uid = (int) openssl_random_pseudo_bytes(4);
echo "Unique ID: " . $uid . " <br>";
} while (!uniqueInTable($table, $field, $uid));
return $uid;
}
<!DOCTYPE html>
<html>
<head>
<title>Fridge Genie || Register</title>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.12.0/jquery.min.js"></script>
</head>
<body>
<div id="main">
<?php
if (!empty($_POST['username']) && !empty($_POST['password'])) {
$username = mysql_real_escape_string($_POST['username']);
$password = mysql_real_escape_string($_POST['password']);
$email = mysql_real_escape_string($_POST['email']);
if (!uniqueInTable('users', 'username', $username)) {
?>
<h1>Error: Username Already Taken</h1>
<p>Please <a href="register.php">click here</a> to try again</p>
<?php
} else {
$registerQuery = registerUser($username, $password, $email);
if ($registerQuery) {
echo "<h1>Success!</h1>";
echo "<p>Please <a href='index.php'>click here</a> to login</p>";
} else {
echo "<h1>Error!</h1>";
echo "<p>Registration failed, <a href='register.php'>click here</a> to try again</p>";
}
}
} else {
