In the following code in between the values I try to enter the database does not store $ file_id why?
<!DOCTYPE html>
<html lang = "es">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>Foro</title>
<link rel="stylesheet" href="css/style.css"/>
<link rel="shortcut icon" href="css/images/logo.png"/>
<script type="text/javascript" src="http://latex.codecogs.com/latexit.js"></script>
<script type="text/javascript">LatexIT.add('p',true);</script>
</head>
<?php
include("conection.php");
session_start();
if(isset($_SESSION["user_name"]))
{
?>
<body>
<div id="agrupar" class="wrapper">
<header id="cabecera"><?php include("banner.php"); ?></header>
<nav id="menu"><?php include("panel.php"); ?></nav>
<section id="seccion">
<?php ob_start();
$user = $_SESSION["user_name"];
$file_id = $_GET["id_file"];
if ($file_id == NULL){ header("Location: index.php");}
$sql = "SELECT * FROM comment WHERE comment_file_id = '".$file_id."'";
$data = mysqli_query($con, $sql) or die( mysqli_error($con));
while($row = mysqli_fetch_array($data))
{
$comment = $row["comment"];
$writtenby = $row["writtenby"];
ob_end_flush();?>
<div class="comment">
<?php
echo "Usuario: <p>$writtenby</p></br>";
echo "Comentario: <p style='font-weight: bold;'>$comment</p>";
?>
</div>
<?php ob_start();
}
ob_end_flush();?>
</section>
<aside id="columna">
<div class="transparent-box">
<div>Discusión sobre:</div>
<div>Publicado por:</div>
</div>
<div id="posting">
<form class="transparent-box" action="<?php ob_start(); echo $_SERVER['PHP_SELF']; ob_end_flush() ?>" method="post" enctype="multipart/form-data">
<textarea class="input-field" name="text" id="textarea" type="text" maxlenght = "140" rows="2" columns="70" placeholder=""/></textarea>
<input type="submit" name="send" class="input-button" value="Comentar" />
</form>
</div>
<?php ob_start();
if(isset($_POST['send']))
{
if(empty($_POST['text']))
{
echo "<script>alert('Comentario de texto vacío.')</script>";
}//end if(empty
else
{
$text = $_POST['text'];
$sql = "INSERT INTO comment (writtenby, comment_file_id, comment) VALUES
('".$user."', '".$file_id."', '".$text."')";
$reg = mysqli_query($con, $sql) or die(mysqli_error($con));
if($reg) {header("Location: forum.php?id_file=".$file_id);}
else {"<script>alert('Ha ocurrido un error.');</script>";}
}
}
ob_end_flush() ?>
</aside>
<footer id="pie"><?php include("footer.php"); ?></footer>
</div>
</body>
<?php
}
else{include("login.php");}
?>
</html>