Fancybox-passing parameters

Good day, hello everyone.

That's what day I'm messing with fancybox and I can't figure out how to pass the values from the modal window to the page where the form was called from. The essence of the problem is that there is a page on which the city is selected. When you click on select city, a modal window opens, where you need to select a city from the list by checking the box (the option can be multiple), and then there is a button select. When you click on the button select-the modal window should disappear and on the page, instead of the label , select the city - is replaced by the city selected from the list.

On the page /index.php the modal window is called, html:

 <div class="bl_categoty">
    <div class="choice_category">Выбрать город</div>
 <div>

Here is the js:

 $(".choice_category").fancybox({
        'padding':6,
        'href':'/modal/categories.php',
         // события при закрытии формы применяется.
         beforeClose: function(){
            console.log("форма закрыта");
            $(".bl_categoty .value_heading").empty().text("ГОРОД");
        }
 });

The modal window is located in /modal/categories.php. This page has a list of cities and a select button.When you click on it it is necessary that the data is transmitted to the page /index.php and substituted in. choice_category. The page's js code /modal/categories.php below:

$(".action_category").click(function(event){
    // value_heading должно записаться выбранный город. - не применяется
    $(".bl_categoty .value_heading").empty().text("ГОРОД");
    parent.jQuery.fancybox.close(); // событие срабатывает

    // не применяется
    $('.choice_category').fancybox({
        beforeClose: function(){
            console.log("*******************");
            $(".bl_categoty .value_heading").empty().text("ГОРОД");
        }
    });
});

How do I pass parameters from a modal window to a page /index.php

Thank you in advance for your answer. I will be very grateful for any help.