There is a modal window with a form, you need to do one more, only with a different form. How to change js?

Question

JavaScript

//popup
$(".callback");
varpopup = $(".popup");
var overlay = $(".overlay");
$(".callback").on("click", function() {
if($(this).hasClass("out"))
{
$(this).removeClass("out").addClass("in" );
overlay.fadeIn();
popup.fadeIn();
}
else
{
$(this).removeClass("in").addClass("out");
overlay.fadeOut();
popup.fadeOut();
}
} );
$(".close_popup").on("click",
overlay.fadeOut();
popup.fadeOut();
});