Checkboxes, javascript and php. Not loading results - php

Question

I have a javascript code that reads from a set of checkboxes and loads a php in case one or more checkboxes are checked. This php will load only the items that are selected.
However, now I click on the checkboxes and nothing happens. I am not sure if the issue is in the php or in the javascript.
Here are the codes:
CHECKBOXES:
function echoCheckboxSet($header, $divClass, $columnName, $setName) {
include ("../commonItems/connection.php");
$checkboxes = $con -> prepare("SELECT DISTINCT $columnName FROM item_descr ORDER BY $columnName ASC");
$checkboxes->execute();
<?php
while ($box = $checkboxes->fetch(PDO::FETCH_ASSOC)):
$boxColumnName = str_replace('_',' ',$box[$columnName]);
?>
<input type='checkbox' class='regularCheckbox' name='<?php echo $setName; ?>' value='<?php echo $box[$columnName]; ?>' />
<font class='similarItemsText'><?php echo $boxColumnName; ?></font>
<br />
<?php
endwhile;
echoCheckBoxSet("COLOR", "colors", "color_base1", "color");
echoCheckBoxSet("PRICE", "prices", "price", "price");
?>
JAVASCRIPT
$(function() {
$("input[type='checkbox']").on('change', function() {
var boxes = [];
// You could save a little time and space by doing this:
var name = this.name;
// critical change on next line
$("input[type='checkbox'][name='"+this.name+"']:checked").each(function() {
boxes.push(this.value);
});
if (boxes.length) {
$(".loadingItems").fadeIn(300);
// Change the name here as well
$(".indexMain").load('indexMain.php?'+this.name+'=' + boxes.join("+"),
function() {
$(".indexMain").fadeIn('slow');
$(".loadingItems").fadeOut(300);
});
} else {
$(".loadingItems").fadeIn(300);
$(".indexMain").load('indexMain.php', function() {
$(".indexMain").fadeIn('slow');
$(".loadingItems").fadeOut(300);
});
}
});
});
INDEXMAIN (indexMain.php)
include('../commonItems/connection.php');
if ($colors != '')
{
$colors = explode(' ', $colors);
$parameters = join(', ', array_fill(0, count($colors), '?'));
$items = $con -> prepare("SELECT * FROM item_descr WHERE color_base1 IN ({$parameters})");
$items ->execute($colors);
$count = $items -> rowCount();
}
while($info = $items->fetch(PDO::FETCH_ASSOC))
{
......... echo everything....
At some point the code was working fine... but now it is not...
Thanks!

Answer 1

indexMain.php is not getting the passed variables.
Adding this at the top made it work:
$colors = $_GET['color'];