I have 2 error, first if i go to login and write wrong Id and password, i see that: Warning: Trying to access array offset on value of type null in C:\xampp\htdocs\Online-BankingPHP\customer_login_process.php on line 18 Warning: Trying to access array offset on value of type null in C:\xampp\htdocs\Online-BankingPHP\customer_login_process.php on line 18 Second: if i open account then approve, apple debit card and Register, after everything i go to login and write my id and password, then show me that: Warning: Undefined array key "Cheque" in C:\xampp\htdocs\Online-BankingPHP\customer_login_process.php on line 43 Error: Invalid template Please can you help me?