Ajax dynamic refresh gives an error when it is called from data.php file [duplicate]

This question already has an answer here:

• PHP: “Notice: Undefined variable” and “Notice: Undefined index” 13 answers

<?php
session_start();
require_once 'class.user.php';
$user_home = new USER();

if(!$user_home->is_logged_in())
{
 $user_home->redirect('index.php');
}

$stmt = $user_home->runQuery("SELECT * FROM tbl_users WHERE userID=:uid");
$stmt->execute(array(":uid"=>$_SESSION['userSession']));
$row = $stmt->fetch(PDO::FETCH_ASSOC);

$proid = $_REQUEST['profile'];
$stmt0 = $user_home->runQuery("SELECT * FROM tbl_users WHERE userName=:uid");
$stmt0->execute(array(":uid"=>$proid));
$row0 = $stmt0->fetch(PDO::FETCH_ASSOC);


$callid = $row0['userID'];
$stmt4 = $user_home->runQuery("SELECT * FROM follow WHERE followrec=:uid");
$stmt4->execute(array(":uid"=>$row0['userID']));
$row4 = $stmt4->fetch(PDO::FETCH_ASSOC);

$stmt7 = $user_home->runQuery("SELECT * FROM tbl_users WHERE userID=:uid");
$stmt7->execute(array(":uid"=>$_SESSION['userSession']));
$row7 = $stmt7->fetch(PDO::FETCH_ASSOC);

?>

 <?php
$host = 'localhost';
$dbname   = 'project';
$username = 'root';
$password = '1234';
$charset = 'utf8';

  $d1 = $row7['userID'];
       $d3 = $row4['followrec'];
       $d4 = $row0['userID'];
       $d2 = "";
       $d5 = "";
try {
    $pdo = new PDO("mysql:host=$host;dbname=$dbname", $username, $password);




    $usid = ($row['userID']);
    $sql1 = "SELECT 
    messages.rec ,messages.send,messages.msg,messages.post_time,tbl_users.userID,tbl_users.Fname,tbl_users.Lname 
 FROM 
      messages , tbl_users 
 WHERE 
      messages.send=tbl_users.userID 
      AND messages.send IN ('$d1','$d4')
      AND messages.rec IN ('$d1','$d4')

 ORDER BY 
      messages.id";



     $q1 = $pdo->prepare($sql1);
    $q1->execute([$usid]);
    $q1->setFetchMode(PDO::FETCH_ASSOC);






} catch (PDOException $e) {
    die("Could not connect to the database $dbname :" . $e->getMessage());
}

?>



<div id="auto_load_div"></div>


   <script type="text/javascript" src="http://code.jquery.com/jquery-latest.min.js"></script>
   <script>
      function auto_load(){
        $.ajax({
          url: "data.php",
          cache: false,
          success: function(data){
             $("#auto_load_div").html(data);
          } 
        });
      }

      $(document).ready(function(){

        auto_load(); //Call auto_load() function when DOM is Ready

      });

      //Refresh auto_load() function after 10000 milliseconds
      setInterval(auto_load,10000);
   </script>
 </body>
</html>

---

data.php

---

        <?php while ($row1 = $q1->fetch()): ?>
           <?php  $a=$row1['rec'];
                       $d4 = $row0['userID'];

                 if ($a==$d4)
                 {


                      include ("msgrec.php");

                 }
                 else 
                       include ("msgsent.php");
                ?><?php endwhile; ?>            

when I include data.php in the first file it runs the code means it fetch the data but whenever I put the code in data.php it gives an error to me

Notice: Undefined variable: q1 in E:wampwwwprojectdocumentationdata.php on line 1

---

( ! ) Fatal error: Call to a member function fetch() on a non-object in E:wampwwwprojectdocumentationdata.php on line 1