bmspage/includes/insert_event.php

<?php
	include "db_config.php";
$conn = mysqli_connect($servername, $username, $password, $db);

$unit = mysqli_real_escape_string($conn, $_POST['unit']);
$start_date_time = mysqli_real_escape_string($conn, $_POST['start_date_time']);
$description = $_POST['description'];
$is_ongoing = mysqli_real_escape_string($conn, $_POST['is_ongoing']);
$end_date_time = mysqli_real_escape_string($conn, $_POST['end_date_time']);
$alert = mysqli_real_escape_string($conn, $_POST['alert']);
$user = mysqli_real_escape_string($conn, $_POST['user']);

//Insert event to events table
$event = "INSERT INTO events (unit_id, date_time_start, description, is_ongoing, date_time_end, alert_id, user) VALUES ('$unit','$start_date_time', '$description', '$is_ongoing', '$end_date_time', '$alert', '$user')";

//MySQL queries to get Unit Name and Alert Name for the Email
$unitname_query = "SELECT unit_name FROM units WHERE unit_id=".$_POST['unit']."";
$unitname_query_run = mysqli_query($conn, $unitname_query);
$unitname_array = mysqli_fetch_assoc($unitname_query_run);
$unitname = $unitname_array['unit_name'];
$alertname_query = "SELECT alert_name FROM alerts WHERE alert_id=".$_POST['alert']."";
$alertname_query_run = mysqli_query($conn, $alertname_query);
$alertname_array = mysqli_fetch_assoc($alertname_query_run);
$alertname = $alertname_array['alert_name'];

//If successful, redirect back to index.php and send email, else tell user that it failed.
$result = mysqli_query($conn, $event);
if($result){
        echo("Event added, redirecting...");
        sleep (2);
        header('Location: ../index.php');
        //Get inserted Event ID
        $event_id = $conn->insert_id;
				//Set Email Info
        $to = "TO-EMAIL@DOMAIN.COM";
        $subject = "New BMS Alert: ".$unitname." ".$alertname."";
        $headers = "From: FROM-EMAIL@DOMAIN.COM";
        $message = "BMS Unit: ".$unitname." \n Type of Alert: ".$alertname." \n Start Date / Time: ".$start_date_time." \n End Date / Time: ".$end_date_time." \n Description: ".$description." \n Created by: ".$user." \n Event Link: https://DOMAIN.com/bms/viewevent.php?eventid=$event_id \n \n This message generated by https://DOMAIN.com/bms";
				//WordWrap the message
				$message_wrapped = wordwrap($message, 70, "\n", true);
        //Send the email
        mail($to,$subject,$message_wrapped,$headers);
} else{
        echo('Error! Please <a href="javascript:history.back()">go back</a> and try again');
}
        $conn->close();
?>