XMLHttpRequest not working on button click null - html

Question

I have a page and when I click on this page with "trigger" I can print the "#content" page. but I want it to return to the "home" I want with the "BACK" button on the page that comes up, but it just doesn't work. Where am I making the mistake?
index.php
<div class="app-content content" id="content">
<?php require 'home' ?></div>
home.php
<div id="kasaButton">
<a type="button" href="#" data-target="contact"> Contact</a>
<a type="button" href="#" data-target="gallery"> Gallery</a>
</div>
<div class="card">
<table class="datatables-basic table">
<thead>
<tr>
<th>İD</th>
<th>NAME</th>
</tr>
</thead>
<tbody>
<tr>
<td>İD</td>
<td>NAME</td>
</tr>
</tbody>
</table>
</div>
gallery
<div class="card-body">
<form action="" method="post">
<input type="text" class="form-control" placeholder="Cari Adı" value=""/>
<button id="save" type="submit">SAVE</button>
<button id="back" type="button">BACK</button>
</form>
</div>
$(document).ready(function () {
var trigger = $("#kasaButton a"),
container = $("#content");
trigger.on("click", function () {
var $this = $(this)
target = $this.data('target');
container.load(target);
return false;
});
});
$(document).ready(function () {
$("#back").on("click", function () {
$("#content").load('home');
});
})

Answer 1

Just add a div with the id of "content"
here is an example of gallery.php:
<div class="card-body">
<form action="" method="post">
<input type="text" class="form-control" placeholder="Cari Adı" value=""/>
<button id="save" type="submit">SAVE</button>
<button id="back" type="button">BACK</button>
</form>
</div>
<div id="content"></div>
<script>
$(document).ready(function () {
var trigger = $("#kasaButton a"),
container = $("#content");
trigger.on("click", function () {
var $this = $(this)
target = $this.data('target');
container.load(target);
return false;
});
});
$(document).ready(function () {
$("#back").on("click", function () {
$("#content").load('home.php');
});
})
</script>