PHP sending email from an include file - php

Question

I'd like to create an includes file which sends an email to user when he logs in. This is how my users get authenticated:
1- my authenticate include file chooses users password in the database based on the user email the login.php passes.
2- if the user is authenticated i just create 2 session variables user_id and user_name
So what I'd like to do is, once the user is authenticated I would like to call my send_login_email function within my email_function include file.
I'm also planning to create more email functions whereby I send an email to user for other notifications, so it's important for the user_email to be saved in a session variable.
This is what my send email includes file lookslike at the moment:
<?php
require_once('../includes/authenticate.inc.php');
function login_mail($_SESSION['uemail'])
{
$to = $_SESSION['uemail'];
$subject = "login";
$message = <?php $user_name ?>, You have logged in.";
$from = "example#email.com";
$headers = "From:" . $from;
mail($to,$subject,$message,$headers);
}
?>
In my authenticate file I select user details as shown below:
$sql = 'SELECT salt, user_password, user_role, user_name, person_id FROM users WHERE user_email = ?';
$stmt = $conn->stmt_init();
$stmt->prepare($sql);
// bind the input parameter
$stmt->bind_param('s', $user_email);
// bind the result, using a new variable for the password
$stmt->bind_result($salt, $storedPwd, $user_role, $user_name, $person_id);
$stmt->execute();
$stmt->fetch();
and within the if statement that checks if the password is correct i have the following code-I'm also calling the email function here:
$_SESSION['start'] = time();
session_regenerate_id();
header("Location: $redirect");
// get the user's name and id
$_SESSION['name'] = $user_name;
$_SESSION['id'] = $person_id;
$_SESSION['uemail'] = $user_email;
require_once('../includes/email_func.inc.php'); //new stuff
login_mail($_SESSION['uemail']);
When I login sucessfully I do not receive an email.
I'm new to using functions and emails within php and Id really appreciate some help please.
Thank you

Answer 1

Change the function as follows:
function login_mail($to, $user_name)
{
$subject = "login";
$message = "$user_name, You have logged in.";
$from = "example#email.com";
$headers = "From:" . $from;
mail($to,$subject,$message,$headers);
}
Then call it as:
login_mail($_SESSION['uemail'], $user_name);
The arguments of a function must be ordinary variables, not array elements. You were trying to reference $user_name, which didn't exist in the function. And <?php ...?> is not used in ordinary assignments, it's used when switching from HTML output to PHP code.
Make sure you have error reporting enabled, you should have gotten errors from those mistakes.