PHP/SQL/AJAX Checkbox not being serialised despite adding hidden input [duplicate] I am trying to create a form where a client can check off their tasks that automatically saves (AJAX). When the client checks the form, the value of the task's ID is sent to the PHP page. However, if the client unchecks it, even with the exact same code, the value disappears and I don't understand why. Here is my code: index.php Task 0 Name Task 1 Name...