get cross cell product collection magento

$cart = Mage::getModel('checkout/cart')->getQuote();
$productid = array();
$crossc = array();
foreach ($cart->getAllItems() as $item) {
    $productid[] = $item->getProduct()->getId();
foreach($item->getProduct()->getCrossSellProducts() as $crosscell){
$crossc[] = $crosscell['entity_id'];
}
}
$crossce = array_diff($crossc, $productid);
$collection = Mage::getResourceModel('catalog/product_collection')->addAttributeToSelect('*');
$collection->addIdFilter($crossce);
$collection->setPageSize(4);