PDO insert not working correctly - php

Question

When I login it's suppose to insert, but instead does nothing.. On my register php it inserts data to accounts, but when i insert data into online it won't work..
PS- I'm new to PDO so I don't know what i'm doing wrong
<?php
session_start();
if(isset($_SESSION['users']) != ""){
echo '<script type="text/javascript">','index();','</script>';
}
include('../php/dbConnect.php');
$username = $_POST['username'];
$password = $_POST['password'];
$query = 'SELECT * FROM `accounts` WHERE username = ?';
$queryprepare = $conn->prepare($query);
$queryprepare->bindParam(1, $username, PDO::PARAM_STR);
$queryprepare->execute();
$row = $queryprepare->fetch();
if($row['password'] == md5($password))
{
$_SESSION['online'] = true;
$_SESSION['users'] = $username;
$_SESSION['userid'] = $row['id'];
$_SESSION['name'] = $row['name'];
$_SESSION['age'] = $row['age'];
$_SESSION['image'] = $row['image'];
$check_row = 'SELECT * FROM `online` WHERE username = ?';
$check_row_fetch = $conn->prepare($check_row);
$check_row_fetch->bindParam(1, $username, PDO::PARAM_STR);
$check_row_fetch->execute();
$number_of_rows = $check_row_fetch->rowCount();
if($number_of_rows != 0) {
echo '<script type="text/javascript">','redirect();','</script>';
}
else{
$online_insert = 'INSERT INTO online (username, name, age, image) VALUES (?, ?, ?, ?)';
$online_insert_fetch = $conn->prepare($online_insert);
$online_insert_fetch->bindParam(1, $SESSION['users'], PDO::PARAM_STR);
$online_insert_fetch->bindParam(2, $SESSION['name'], PDO::PARAM_STR);
$online_insert_fetch->bindParam(3, $SESSION['age'], PDO::PARAM_STR);
$online_insert_fetch->bindParam(4, $SESSION['image'], PDO::PARAM_STR);
$online_insert_fetch->execute();
echo '<script type="text/javascript">','redirect();','</script>';
}
}
else{
echo("Wrong Credentials");
}
?>