How to take user input php - php

Question

I'm making an event management system. I dont know what's wrong, it just keeps reloading after I click submit button.
Here's my HTML codes
<?php
session_start();
if (!isset($_SESSION['username'])) {
$_SESSION['msg'] = "You must log in first";
header('location: login.php');
}
if (isset($_GET['logout'])) {
session_destroy();
unset($_SESSION['username']);
header("location: login.php");
}
<div class="header">
<h2>Create Event</h2>
</div>
<form method="post" action="create_event.php">
<div class="input-group">
<label>Event Title</label>
<input type="text" name="event_title" >
</div>
<div class="input-group">
<label>Pick Location</label>
<select name="location">
<option>Alabang</option>
<option>South City</option>
<option>Batangas</option>
<option>Cavite</option>
<option>Laguna</option>
</select>
<div class="input-group">
<label>Address</label>
<textarea rows="4" cols="50" name="address"></textarea>
</div>
<div class="date">
<label>Pick date and time</label>
<input type="date" name="date"></br>
<input type="time" name="time">
</div>
<div class="event_info">
<label>Event Information</label>
<textarea rows="4" cols="50" name="event_info"></textarea>
</div>
<div class="input-group">
<button type="submit" class="btn" name="create_event">Create Event</button>
</div>
</form>
PHP code:
// Create Event
if (isset($_POST['create_event'])) {
// receive all input values from the form
$event_title = mysql_real_escape_string($_POST['event_title']);
$location = mysql_real_escape_string($_POST['location']);
$address = mysql_real_escape_string($_POST['address']);
$date = mysql_real_escape_string($_POST['date']);
$time = mysql_real_escape_string($_POST['time']);
$event_info = mysql_real_escape_string($_POST['event_info']);
$query="select * from `event` where event_title='$_POST[event_title]' or time='$_POST[time]' or date='$_POST[date]'";
$result=mysql_query($query);
$count=mysql_num_rows($result);
if($count>0)
{
array_push($errors, "Already used");
}
// form validation: ensure that the form is correctly filled
if (empty($event_title)) { array_push($errors, "Please input title"); }
if (empty($location)) { array_push($errors, "Location is required"); }
if (empty($address)) { array_push($errors, "Location is required"); }
if (empty($time)) { array_push($errors, "Time is required"); }
if (empty($date)) { array_push($errors, "Date is required"); }
if (empty($event_info)) { array_push($errors, "Date is required"); }
// register user if there are no errors in the form
if (count($errors) == 0) {
$query = "INSERT INTO `event` (event_title,location,address,time,date,event_info) VALUES ('$event_title', '$location','$address','$time','$date','$event_info')";
$result = mysql_query($query);
echo("success");
}
}
I don't think there is anything wrong because if I click the submit button, no errors popup. It just reloads but no data is sent to my database.

Answer 1

Amend in form your submit button like this:
<input type = "submit" name = "create_event" value="create event"/>
Also in action use $_SERVER['PHP_SELF'] variable. Like this...
<form action ="<?php echo
htmlspecialchars($_SERVER['PHP_SELF']);
?>" method = "post">
In database query please use PDO statement it's easy and safe. And also sanitize user input before using it.