$stmt = $link->prepare('SELECT username,email FROM users WHERE username=? or email=? LIMIT 1');  #
			$stmt->bindValue(1, $usr, PDO::PARAM_STR);
			$stmt->bindValue(2, $email, PDO::PARAM_STR);
			$stmt->execute();
			if( (!$result = $stmt->fetch(PDO::FETCH_ASSOC)) > 0) { # [email,username] are not taken
					# OK
					$stmt = $link->prepare('INSERT INTO users (username,email,password) VALUES (?,?,?)');  #
					$stmt->bindValue(1, $usr, PDO::PARAM_STR);
					$stmt->bindValue(2, $email, PDO::PARAM_STR);
					$stmt->bindValue(3, $pass, PDO::PARAM_STR);
					if ($stmt->execute()) {  # success
						$form->success_message("Добре дошъл в системата: <b>".$usr."</b>");
						session_regenerate_id();
					} else {
						$form->add_to_errors('Проблем със заявката за регистрация, моля опитайте по-късно или се свържете с администратор.');
					} # failed
					$link = null; # close pdo when inserted
			} else { $form->add_to_errors('Името или Имейла вече е зает, моля опитайте с друг.'); } # [username,email] taken
			$link = null; # close pdo connection
		}

## LOGIN
			# [*] = id, name, email, password, created_at, theme, last_login_datetime - change to 1
			# limit 1 if foind dont check other rows
			#$stmt = $link->prepare('SELECT username,password FROM users WHERE username=? LIMIT 1');
			$stmt = $link->prepare('SELECT COUNT(*) AS num FROM users WHERE username=? LIMIT 1');
			$stmt->bindValue(1, $usr, PDO::PARAM_STR);
			$stmt->execute();
			 if($result = $stmt->fetch(PDO::FETCH_ASSOC)) { # user found
				if (password_verify($pass, $result['password'])) { # pass is ok [ARGON2ID crypted]
					$stmt = $link->prepare('UPDATE users SET last_login = NOW() WHERE username=? LIMIT 1');
					$stmt->bindValue(1, $usr, PDO::PARAM_STR);
					$stmt->execute();
					# ==============================
					session_regenerate_id(); 			# https:#www.php.net/manual/en/function.session-regenerate-id.php
					$_SESSION["loggedin"] 	= true; 	# Store data in session variables
					$_SESSION["id"] 		= $result['id'];
					$_SESSION["username"] 	= $usr;
					$_SESSION["theme"] 		= $result['theme'];
					#$form->printr($_SESSION); 		# for debug
					header("location: profile.php");
					$link = null; # close pdo after login
					# ==============================
				} else { $form->error_message("Паролата не е вярна."); }
			} else { $form->error_message("Няма такъв акаунт в системата."); }
			$link = null; # close pdo after failure