Not able to create new directory with variable (PHP) - php

Question

Hello I'm trying to create a directory in the users/ folder. When the user registers a vpb_save_details.php is being opened. And mkdir is ran to create a user with the username as directory name.
The user is being registered as normal but the problem that no directory is created, not even the /user directory.
If i run this code:
<?php
mkdir("blah", 0777);
?>
The directory bla is created, but if I run my code vpb_save_details.php, nothing happens.
This is a part of the code:
//If the user is validated and every thing is alright, then save the user details and display success message to the user
//otherwise, display error message to the user
if ($vpb_error == '')
{
//Encrypt user information with Base64 before saving them to a file
if(fwrite($vpb_database, "\r\n".base64_encode($fullname)."::::::::::".base64_encode($username)."::::::::::".base64_encode($email)."::::::::::".base64_encode($encrypted_user_password).""))
{
echo '<font style="font-size:0px;">completed</font>';
echo '<div class="info">Congrats <b>'.$fullname.'</b>, you have registered successful. <br>You may now click on the login button to log into your account.<br>Thanks.</div>';
//
// HERE! I create a folder in the users directory with the variable $username as username
//
$newUserName = $username;
$userPath = "users/".$newUserName;
mkdir("$userPath", 0777);
//copy("index.php",$userPath/index.php);
}
else
{
echo '<div class="info">Sorry, your account creation was unsuccessful, please try again (1).</div>';
}
}
else
{
echo $vpb_error;
}
fclose($vpb_database);
I have absolutely no idea what the problem could be? the code:
$newUserName = $username;
$userPath = "users/".$newUserName;
mkdir("$userPath", 0777);
Should work just fine, or am I missing a small detail?

Answer 1

Remove the quotes.
mkdir($userPath, 0777);