Preventing double HTTP POST

Question

I have made a little app for signing up for an event. User input their data and click \"sign me in\".

Now sometimes people are double in the database, the exact sam

Answer 1

A user-side solution is to disable the submission button via Javascript after the first click.

It has drawbacks, but I see it often used on e-commerce websites.

But, it won't never replace a real server-side validation.