form submission on product detail page - php

Question

I have following code on the top of product detail page
<?php
include("include/connection.php");
session_start();
$ses_id = session_id();
$ID = (int)$_REQUEST['id'];
if (!isset ($_POST['submit']))
{
?>
<div class="row">
<div class="span9">
<div class="span6 ">
<h4>Review(0)</h4>
<p>There are no review for this product</p>
<h4>Write a Review</h4>
<form method="POST" action="<?php echo $_SERVER['PHP_SELF'];?>">
<p>Your Name:</p>
<input type="text" id="txtname" name="Rname" placeholder="write your name..." />
<p>Your Review</p>
Excelent<input type="radio" name="reviewbtn" class="radio" value="Excelent" />
Good<input type="radio" class="radio" name="reviewbtn" value="Good" />
Poor<input type="radio" class="radio" name="reviewbtn" value="Poor" /><br/>
<textarea id="txtreview" name="txtbx" cols="50" rows="10"
class="container-fluid"></textarea>
<input type="submit" value="submit" class="btn" />
</form>
</div>
</div>
</div>
<?php
} else {
$Rname = mysql_real_escape_string(stripslashes(htmlentities($_POST["Rname"])));
$Reviewbtn = $_POST["reviewbtn"];
$Txtbox= mysql_real_escape_string(stripslashes(htmlentities($_POST["txtbx"])));
$sql=mysql_query ("INSERT INTO reviews (Name, Comments,Rating) VALUES('$Rname','$Reviewbtn','$Txtbox')", $con) or die (mysql_error());
echo "Record added succesfully. You will be redirected to previous page in 5 seconds";
header( "refresh:5;url= product_detail.php" );
}
mysql_close($con);
?>
here I am getting error
Notice: Undefined index: id in \product_detail.php on line 5
( which is $ID = (int)$_REQUEST['id']; )
basically I am building a rating form on a product,please if someone can modify the code so form submission could be done using ajax jquery call so page should not load again

Answer 1

remove int from it there no need of it.
$ID = $_REQUEST['id'];

Answer 2

There is no Element named ID in your form
So when you are going to catch this it occurred error
$ID = $_REQUEST['id'];
^ provide actual form element's name here
When you coming to this page from previous page it is not showing error
after submitting from it is showing error.
If it is, add an hidden element into your form
<input type='hidden' name='id' value="<?php echo $ID; ?>">
It will solve the problem

Answer 3

Use some other word as name attribute rather than naming it as id you can set it to user_id or something else you want,because it is not a good practice
if(isset($_REQUEST['user_id'])){
$ID = $_REQUEST['user_id'];
}