Can't find the right coding for calculation - URGENT!

@mikemoynihan99 thanks, this might indeed help for the display!

But what concerns the calculations, what code functions do I have to use to - based on what you said in your very first reply - run the query, verify the total ticket number and perform the substraction?

Could you possibly write me an example? I know I’m asking a lot, but my website is ready to be launched as soon as I solved this problem - I am really struggling with it…