How to delete an eav product attribute programmatically

Question

i want to delete a product attribute from eav table pragmatically. I was getting a code which was delete customer attribute.

I want just like this code ,which was delete product attribute.

<?php
error_reporting(E_ALL | E_STRICT);
$mageFilename = 'app/Mage.php';
require_once $mageFilename;
Mage::setIsDeveloperMode(true);
umask(0);
Mage::app();
Mage::app()->setCurrentStore(Mage::getModel('core/store')->load(Mage_Core_Model_App::ADMIN_STORE_ID));

$setup = new Mage_Eav_Model_Entity_Setup('core_setup');

    try {
        $custAttr = 'user_name';  // here enter your attribute name which you want to remove

        $setup->removeAttribute('customer', $custAttr);
        echo $custAttr." attribute is removed";
    }
        catch (Mage_Core_Exception $e) {
        $this->_fault('data_invalid', $e->getMessage());
    }

?>

please help me.