My first snippet - zipcode radius

<div class="panel">
		<div class="panel-header"><h1>US Zipcode distance search</h1></div>
		<div class="panel-content">
			[[!FormIt?
			&hooks=`zipsearch, successMessage`
			&successMessage=`this was a success`
			]]
			
			<form action="[[~[[*id]]]]" method='POST'>
				<label for='zipcode'>Enter the zipcode (US)</label> [[%zipsearch.zipcode]]
                                 <input type='text' name='zipcode' id='zipcode' >
				<div class="helptext">eg. 20007,20306</div>
				<label for='radius'>Radius</label>
				<select name='radius' id='radius' > [[%zipsearch.radius]]
					<option value='5'>5 miles</option>
					<option value='10'>10 miles</option>
					<option value='15'>15 miles</option>
					<option value='20'>20 miles</option>
					<option value='25'>25 miles</option>
					<option value='30'>30 miles</option>
					<option value='35'>35 miles</option>
					<option value='40'>40 miles</option>
				</select>
				<div id="actions">
					<input class="button" type='submit' value='Search' class='clear'>
				</div>
			</form>	
		</div>
		[[$zipresult]]
		[[+fi.successMessage]]
	</div>

		$modx->getOption('site_url').'includes/clsZipCodeRange.php';
		
		$modx->setPlaceholder('zipcode',$sSearchZipCode);
		$modx->setPlaceholder('radius',$iRadius);
		
		$sQuery = $modx->db->query('SELECT zipcode FROM `zipcodes`');
		$objZipCodeRange = new ZipCodesRange($sSearchZipCode, $iRadius);
	
		$myChunk = "zipresult";

		if(isset($objZipCodeRange)){
			$totalZipcodesFound = count($objZipCodeRange->zipCodes);
			if($totalZipcodesFound > 0){
				foreach ($objZipCodeRange->zipCodes as $ZipData){
				$values = array($ZipData['ZIPCODE'], ',');
				}
				$output = $modx->parseChunk($zipresult, $values, '[+', '+]');
 
				return $output;
			}}

/* This needs to be a path, not a URL. 
   Might need MODX_CORE_PATH instead, 
   depending on where the file is */
$path = MODX_BASE_PATH . 'includes/clsZipCodeRange.php';
if (file_exists($path)) {
    include $path;
} else {
    return 'File Not found at: ' . $path;
}

/* Get the submitted values */
$sSearchZipCode = $hook->getValue('zipcode');
$iRadius = $hook->getValue('radius');

/* I'm assuming that these placeholders are in the Tpl chunk */
$modx->setPlaceholder('zipcode', $sSearchZipCode);
$modx->setPlaceholder('radius', $iRadius);


$objZipCodeRange = new ZipCodesRange($sSearchZipCode, $iRadius);

if (empty($objZipCodeRange)) {
    return 'objZipCodeRange is empty';
}

$myChunk = "zipresult";

/* next line is incorrect, but the variable $sQuery is never used */
// $sQuery = $modx->db->query('SELECT zipcode FROM `zipcodes`');

$totalZipcodesFound = count($objZipCodeRange->zipCodes);
if ($totalZipcodesFound > 0) {
    foreach ($objZipCodeRange->zipCodes as $ZipData) {
        
        /* $values needs to be an associative array of keys and values, e.g.,  */
        /*
        $values = array(
            'placeholder1' => $value1,
            'placeholder2' => $value2,
        );
        */
        
        /* Guessing here */
        $values = array();
        foreach ($ZipData as $key=>$value) {
           $values[$key] = $value;
        }
        /*$values = array(
            $ZipData['ZIPCODE'],
            ','
        );*/
    }
    /* If this is revolution, the placeholders in the chunk should be in
       the form [[+placeholderName]] */
    $output .= $modx->getChunk($myChunk, $values);

    return $output;
}