Magento: How to get product rating and review

code for getting ratings and reviews for any particular product.

/* Getting reviews collection object
 */
 $productId = $product->getId();
 $reviews = Mage::getModel('review/review')
 ->getResourceCollection()
 ->addStoreFilter(Mage::app()->getStore()->getId())
 ->addEntityFilter('product', $productId)
 ->addStatusFilter(Mage_Review_Model_Review::STATUS_APPROVED)
 ->setDateOrder()
 ->addRateVotes();
 /**
 * Getting average of ratings/reviews
 */
 $avg = 0;
 $ratings = array();
 if (count($reviews) > 0) {
 foreach ($reviews->getItems() as $review) {
 foreach( $review->getRatingVotes() as $vote ) {
 $ratings[] = $vote->getPercent();
 }
 }
 $avg = array_sum($ratings)/count($ratings);
 }

for display

<?php if($avg): ?>
 <div class="rating-box" style="float:left;">
 <div class="rating" style="width: <?php echo ceil($avg) ; ?>%;"></div>
 </div>
 <?php endif; ?>