How to get a list of page ids based on the value of a tv

if ( $tvval === $query ) {
        // if the requested value is the same as the value of that tv, add it to the array
        $resources[] += $tvresource->get('contentid');
    }

<?php
$query = $_POST['region']; // The value submitted by the selectbox/form
$resources = array(); // all resource ids that have the requested value
$tvresources = $modx->getCollection('modTemplateVarResource', array('tmplvarid' => 36)); // find all resouces that have a value in the tv with id = 36
foreach ($tvresources as $tvresource) {
    $tvval = $tvresource->get('value'); // get the value of the tv, needed for the following check
    if ($tvval === $query) {
        // if the requested value is the same as the value of that tv, add it to the array
        $resources[] += $tvresource->get('contentid');
    }
}
// return a comma separated list of resource ids for getResources
return implode(',', $resources);

    if ( $tvval === $query ) ) {

return implode(',' $resources);