sul server è abilitata la visualizzazione degli errori, e "non vengono segnalati" (cmq) controllo

questa e la parte di codice che crea la cartella e gestisce l'upload

include('./include/class.upload.php');


codice:
$nomecartella = $last_id.$nomecartella.$last_id;
$cartok = '../CARTELLA/'.$nomecartella;

mkdir($cartok, 777);
chmod($cartok, 0777);

	$handle = new Upload($_FILES['logo']);
	if ($handle->uploaded) {
	$handle->image_resize = true;
	$handle->image_x = 155;
	$handle->image_ratio_y = true;
	$handle->Process($cartok);
	$logo_corso = $handle->file_dst_name;
	}

	$handle = new Upload($_FILES['logo_sponsor']);
	if ($handle->uploaded) {
	$handle->image_resize = true;
	$handle->image_x = 155;
	$handle->image_ratio_y = true;
	$handle->Process($cartok);
	$logo_sponsor = $handle->file_dst_name;
	}
	
	$handle = new Upload($_FILES['logo_organizzatore']);
	if ($handle->uploaded) {
	$handle->image_resize = true;
	$handle->image_x = 155;
	$handle->image_ratio_y = true;
	$handle->Process($cartok);
	$logo_organizzatore = $handle->file_dst_name;
	}	
	$handle = new Upload($_FILES['banner_corso']);
	if ($handle->uploaded) {
	$handle->file_new_name_body = $last_id.'banner'.$last_id;
	$handle->image_resize = false;
//	$handle->image_x = 560;
//	$handle->image_y = 90;
	$handle->Process('../CARTELLA/BANNER/');
	$banner_corso = $handle->file_dst_name;
	}