Fatal error: Uncaught Error: Undefined class constant 'TICKET_DBCON_URL' in C:\xampp\htdocs\lh-th\class\class_tickets.php:19 Stack trace: #0 C:\xampp\htdocs\lh-th\tickets.php(20): Tickets->__construct() #1 {main} thrown in C:\xampp\htdocs\lh-th\class\class_tickets.php on line 19