How to submit the form on SELECT CHANGE event?

Friends, there are several forms on the page and the script which sends the AJAX method, the data for each form separately. Here. Sent the form by clicking on the SEND button. On the submit event.
Question. How to send form - INIT script to do the SELECT CHANGE event?

Here is one of the forms the SEND button I want to remove it, so such a task.
<form id="ajax-form" class="ajax-form">
<select name="date">
<option value="0" selected="">All</option>
<option value="2018">2018</option>
<option value="2017">2017</option>
<option value="2017">2017</option>

<select name="event">
<option value="0" selected>All</option>
<option value="1">1</option>
<option value="2">2</option>
<option value="3">3</option>

<a href="#" data-type="submit" class="theme-button">SEND</a>

Here is the code itself, each bypasses in all forms, and sends the data through the serialize on (code simplified for understanding).
$.fn.forms = function (o) {
 return this.each(function () {
 var th = $(this),
 _ ='forms') || {
 controls: 'a[data-type=reset],a[data-type=submit]',

 submitFu: function () {
 data: _.form.serialize(),
 controlsFu: function () {
 $(_.controls, _.form).each(function () {
 var th = $(this)
 .bind('click', function () {
 return false
 init: function () {
 _.form =
 .bind('submit', function () {
} || _.init( ={
 forms: _
 typeof o == 'object' && $.extend(_, o)

Trying to do so, after this code
$('select').on('change', function() {

But not works :( of course you Can call the trigger click on the button, and the button to display:none but I want to remove the button altogether. How to run INIT script in the CHAGE event of SELECT? Instead of the SUBMIT button.
PLEASE tell me!!!
April 4th 20 at 00:50
1 answer
April 4th 20 at 00:52
Figured out by guesswork and intuition, it was necessary to add code to BIND still BIND on CHANGE

.bind('change', function () {

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