How to add to cart configurable product in magento programmatically ?

<?php

include 'app/Mage.php';

Mage::app();

// Need for start the session

Mage::getSingleton('core/session', array('name' => 'frontend'));

try {

    $product_id = '389';

    $product = Mage::getModel('catalog/product')->load($product_id);

    $cart = Mage::getModel('checkout/cart');

    $cart->init();

    $params = array(

        'product' => $product_id,

        'super_attribute' => array(

            1102 => 351,              
        ),

        'qty' => 1,

    );

    $cart->addProduct($product, $params);

    $cart->save();

    Mage::getSingleton('checkout/session')->setCartWasUpdated(true);

    Mage::getSingleton('core/session')->addSuccess('Product added successfully');

    header('Location: ' . 'index.php/checkout/cart/');

} catch (Exception $e) {

    echo $e->getMessage();

}

?>