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

$tvId = 1; //the tv id I want to get
$tv = $modx->getObject('modTemplateVar',$tvId);
$tvContent = $tv->getValue($pageId);
return $tvContent;

<?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);

$tvresources = $modx->getCollection('modTemplateVarResource', array('tmplvarid' => 36,'value' => $query));