The problem is that if you press the button (1) another button appears (2), and when you press the button (1) again, buttons (2) appear next to the button (2), and only one button appears (2 ) and was not duplicated.
$(html).appendTo('#body'); $('#knopka_1').click(function () { form_i(); })
That is, when you press the button (1), the function is called where the button (2) is registered.
PS This is javascript.