PHP User Registration Page

Question

I built a new registration page for a php app. Ths processes the user registration page. After user has submitted user information, it doesnt redirect to "index.php" but rather to a blank page. PLease

<?php
    
    require 'database-config.php';
    
    session_start();

       $username = $_POST['username'];
       $password = $_POST['password'];
       $password = md5($password);
       $user_access_level = $_POST['radios'];
       $dt = date('d-m-Y');
       
       $query = $dbh->prepare("SELECT * FROM users WHERE username=:username");
       $query->execute(array(':username' => $username));

       if($query != false){
           while($q = $query -> fetch(PDO::FETCH_ASSOC)){
               $error = '<br><div class="info">Sorry, the username <b>'.$username.'</b> is already in use. Please enter a different username of your choice to proceed. Thanks.</div><br>';
           }    
       }
       
       else {
           $insert = $dbh->prepare('INSERT INTO users(username, password, user_access_level, date) VALUES(:username, :password, :user_access_level, :date)');
           $insert->execute(array(':username'=>$username,':password'=>$password,':user_access_level'=>$user_access_level,':date'=>$dt));
           
           if(insert!=false){
               header("location: index.php");
           }
           else{
               $error = '<br><div class="info">Sorry, your account could not be created at the moment. Please try again or contact the site admin to report this error if the problem persist. Thanks.</div><br>';
           }
           
       }
   
    
    
?>

Answer 1

You have a syntax error. You missing the $ on insert => $insert:

// $insert, not insert
if(insert!=false){
    header("location: index.php");

Should be:

if($insert!=false){
        header("location: index.php");
        // exit on header is best practice
        exit;
    }

Turn on ini_set('display_errors',1); error_reporting(E_ALL);. You may have more errors you are missing. This error would have been noted if you had errors on.