php page redirection to another page - php

Question

i am using html canvas page for drawing online and i am linking it with save.php file which saves the drawing data from the canvas on my database
and this is the code of save.php
if (isset($GLOBALS["HTTP_RAW_POST_DATA"]))
{
// Get the data
$imageData=$GLOBALS['HTTP_RAW_POST_DATA'];
//echo "ok1";
// Remove the headers (data:,) part.
// A real application should use them according to needs such as to check image type
$filteredData=substr($imageData, strpos($imageData, ",")+1);
// Need to decode before saving since the data we received is already base64 encoded
$unencodedData=base64_decode($filteredData);
//echo "unencodedData".$unencodedData;
// Save file. This example uses a hard coded filename for testing,
// but a real application can specify filename in POST variable
$file = ''.rand().'';
$fp = fopen( $file.'.png', 'wb' );
fwrite( $fp, $unencodedData);
fclose( $fp );
//echo "ok2";
$servername = "example";
$username = "example";
$password = "example";
$dbname = "example";
// Create connection
$conn = new mysqli($servername, $username, $password, $dbname);
// Check connection
if ($conn->connect_error) {
die("Connection failed: " . $conn->connect_error);
}
//$usr = wp_get_current_user();
//$uid = (int) $usr->ID;
//echo "ok3";
//global $current_user1;
//$current_user = wp_get_current_user();
//global $current_user;
//get_currentuserinfo();
$root = dirname(dirname(__FILE__));
if (file_exists($root.'/wp-load.php')) {
require_once($root.'/wp-load.php');
//echo "EXISTS";
}
$user_id = get_current_user_id();
//echo "ok4";
$content1 = '<img class="alignnone wp-image-11" src="http://example.com/wp-includes/'.$file.'.png" alt="" />';
// $usr=get_current_user_id();
$sql = "INSERT INTO wp_njvt_posts (post_date,post_date_gmt,post_author, post_content, post_title, post_excerpt, post_password, post_name, to_ping, pinged, post_content_filtered, guid, post_mime_type)
VALUES (NOW(),NOW(),'$user_id','$content1', '', '', '','$file','','','','http://www.example.com/?p=$file','')";
$row_id = 0;
// $usr=0;
if ($conn->query($sql) === TRUE) {
echo "".$file.".png";
$row_id = $conn->insert_id;
} else {
echo "Error: " . $sql . "<br>" . $conn->error;
}
$sql2 = "UPDATE wp_njvt_posts SET guid = 'http://www.example.com/?p=$row_id' WHERE ID = $row_id" ;
if ($conn->query($sql2) === TRUE) {
echo " ***your drawing was published SUCCESSFULY!*** ";
//header("Location: http://www.example.com/?p=$row_id");
} else {
echo "Error:". $sql2 . "<br>" . $conn->error;
}
$conn->close();
}
now the drawing gets a link like http://www.example.com/?p=$row_id and i tried redirect the user after publishing the drawing to that link and i tried it with
header("Location: http://www.example.com/?p=$row_id");
but it is not working with me!
any other solutions other than (header) ?