how to post login array error within the originating page - authentication

Question

Hi how do you post the login error message within the originating page where the user was attempting to login ?
Below I was able to stay on the current page if user login successfully but for login error it will obviously just go to the logonprocess page and display the error message.
Sorry that I remove a lot of validation below as the codes can really be very long.
Index.php
<?php
//set the session cookie parameter
ini_set("session.save_path", "sessionData");
session_start();
?>
<?php
if (!isset($_SESSION['uName'])) { ?>
<form method="post" action="logonProcess.php">
<div>Username <input type="text" name="userName" placeholder="Username"></div>
<div>Password <input type="password" name="pwd" placeholder="Password"></div>
<div><input type="submit" value="Logon"></div>
</form>
<?php } else { }?>
<?php
if (isset($_SESSION['uName'])) {
$username = $_SESSION['uName'];
echo "<p>Welcome $username</p>\n";
?>
Logout</br></br>
LogonProcess.php
$loginerror = array();
if (empty($username)) {
$loginerror[] = "You have not entered all of the required fields";
}
elseif (strlen($passWD) < 8) {
$loginerror[] = "You have not entered all of the required fields";
}
if (!empty($loginerror))
for ($a=0;$a<count($loginerror);$a++)
{
echo "$loginerror[$a] <br />\n";
}
else
if (mysqli_stmt_fetch($stmt))
{
if (password_verify($passWD, $passWDHash))
{
$_SESSION['uName'] = $username;
echo "<p>Login successful</p>";
header('Location: ' . $_SERVER['HTTP_REFERER']);
}
else
{
echo "<p>Please try to login again</p>";
}

Answer 1

why dont you put ur login error in $_SESSION["login_error"] and check in ur origin page if the session exits show the error then destroy the session after it.