مشكلة في ارسال البيانات لقاعدة البيانات

السلام عليكم اخواني الاعزاء لدي مشكلة لا اعرفها وهي ان البيانات لا يتم ارسالها للقاعدة

الجدول

CREATE TABLE `messages_groups` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`sender_id` varchar(256) NOT NULL,
`sender_name` varchar(256) NOT NULL,
`picture` varchar(256) NOT NULL,
`group` varchar(256) NOT NULL,
`message` text NOT NULL,
PRIMARY KEY ( `id` )
)ENGINE=MyISAM DEFAULT CHARSET=utf8;

connect_file.php

<?php
$DATABASE_HOST = 'localhost';
$DATABASE_USER = 'root';
$DATABASE_PASS = '';
$DATABASE_NAME = 'test';
$db = mysqli_connect($DATABASE_HOST, $DATABASE_USER, $DATABASE_PASS, $DATABASE_NAME);
// Check connection
if($db === false){
    die("ERROR: Could not connect. " . mysqli_connect_error());
}
?>

index.php

<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.8.0/jquery.min.js"></script>
	<script type="text/javascript">
		$(document).ready(function() {

			//##### Add record when Add Record Button is click #########
			$("#messages_form_groups").submit(function(e) {
				e.preventDefault();
				//build a post data structure
				var sender_id = $("#my_sender_id").val(),
					sender_name = $("#my_sender_name").val(),
					picture = $("#my_picture").val(),
					group = $("#my_group").val(),
					message = $("#my_message").val();

				if (sender_id == '' || sender_name == '' || picture == '' || group == '' || message == '') {
					alert("All fields are required");
					return false;
				}

				jQuery.ajax({
					type: "POST", // Post / Get method
					url: "response.php", //Where form data is sent on submission
					dataType: "text", // Data type, HTML, json etc.
					data: {
						sender_id: sender_id,
						sender_name: sender_name,
						picture: picture,
						group: group,
						message: message
					}, //Form variables
					success: function(response) {
						$("#norec").hide();
						$("#responds").append(response);
						$('#messages_form_groups').trigger('reset');
					},
					error: function(xhr, ajaxOptions, thrownError) {
						alert(thrownError);
					}
				});
			});

		});
	</script>

<form  id="messages_form_groups" >
<input name="sender_id" id="my_sender_id" value="test"><br>
<input name="sender_name" id="my_sender_name" value="test"><br>
<input name="picture" id="my_picture" value="test"><br>
<input name="group" id="my_group" value="test"><br>
<textarea name="message" id="my_message"></textarea>
<br>
<INPUT type="submit" id="FormSubmit" >
</form>

<?php
include_once("connect_file.php");  

		$Result = mysqli_query($db, "SELECT * FROM messages_groups");
		$count = mysqli_num_rows($Result);
		?>
		<table id="responds" border="1">
			<tr>
				<th>#</th>
				<th>sender_id</th>
				<th>sender_name</th>
				<th>picture</th>
				<th>group</th>
				<th>Message</th>
			</tr>
			<?php if ($count > 0) : ?>
				<?php while ($row = mysqli_fetch_array($Result)) : ?>
					<tr>
						<td><?= $row['id'] ?></td>
						<td><?= $row['sender_id'] ?></td>
						<td><?= $row['sender_name'] ?></td>
						<td><?= $row['picture'] ?></td>
						<td><?= $row['group'] ?></td>
						<td><?= $row['Message'] ?></td>
					</tr>
				<?php endwhile; ?>
			<?php else : ?>

				<tr id="norec">
					<td colspan="4">No Records</td>
				</tr>

			<?php endif; ?>
		</table>

response.php

<?php
//include db configuration file
include_once("connect_file.php");
 
if(isset($_POST["message"]) && strlen($_POST["message"])>0) 
{	
	$sender_id = mysqli_real_escape_string($db, $_POST["sender_id"]); 
	$sender_name = mysqli_real_escape_string($db, $_POST["sender_name"]);
	$picture = mysqli_real_escape_string($db, $_POST["picture"]);
	$group = mysqli_real_escape_string($db, $_POST["group"]); 
    $message = mysqli_real_escape_string($db, $_POST["message"]);  
    $query = "INSERT INTO messages_groups(sender_id, sender_name, picture, group, message) VALUES ('".$sender_id."', '".$sender_name."','".$picture."','".$group."','".$message."')"; 
	if(mysqli_query($db, $query))
	{
		$id = mysqli_insert_id($db);
		$result = "<tr>
						<td>$id</td>
						<td>$sender_id</td>
						<td>$sender_name</td>
						<td>$picture</td>
						<td>$group</td>
						<td>$message</td>
					</tr>";
		echo $result; 
	}
 
}
?>