Check if product is new using observer

observer.php

<?php
class Some_Module_Model_Observer{
protected $isNew = false;
public function beforeSave($observer) {
    $product = $observer->getEvent()->getProduct();
    if($product->isObjectNew()){
        $this->isNew = true;
    }
}
public function afterSave($observer) {
    $product = $observer->getEvent()->getProduct();
    if($this->isNew){
        /*Add Logic Here*/
    }
}

}