Check the customer password field Magento 1.9

    $email='test@gmail.com';
    $customer =Mage::getModel('customer/customer')
    ->setWebsiteId(Mage::app()->getStore()
    ->getWebsiteId())
    ->loadByEmail($email);
    $hash= $customer->getPasswordHash();

    Mage::helper('core')->validateHash($currentpassword, $hash);