jquery - show textbox when checkbox checked

Question

I have this form

Answer 1

As your dividers are placed next to your checkboxes, you simply need to use jQuery's next() method to select the correct elements:

if ($(this).is(':checked'))
    $(this).next('div.max_tickets').show();
else
    $(this).next('div.max_tickets').hide();

Updated Codepen demo.

From the documentation (linked above), the next() method selects:

...the immediately following sibling of each element in the set of matched elements. If a selector is provided, it retrieves the next sibling only if it matches that selector.

Here we're selecting the next div.max_tickets element. However in your case just using next() with no parameters would suffice.