function match_files_in_directory($dir, $extension = '.jpg'){
    $ary    =   array();
 
    if ($handle = opendir($dir)) {
        while (false !== ($file = readdir($handle))) {
            if ($file != "." && $file != ".." && strpos($file, $extension) > -1 ) {
                $ary[]  =   $file;
            }
        }
        closedir($handle);
    }
 
    return $ary;
}