Dont want to merge old carts items with current quote

Hi,guys
Here i explain how you can prevent the cart from the old session from merging
into the cart of the current session at the point when the customer login.
Problem is, that a customer could basically be done shopping, logs in to their
account and their cart gets filled with their old “last logged in” cart items as
well as the ones they just recently picked.
To prevent this from happening, here’s what I did
The function loadCustomerQuote() in the observer observes the event customer_login
and merges the current session quote with the last login quote object.
you can see  loadCustomerQuote() in :
Mage_Checkout_Model_Observer.
Mage_Checkout_Model_Session.

public function loadCustomerQuote()
{
$customerQuote = Mage::getModel('sales/quote')
         ->setStoreId(Mage::app()->getStore()->getId())
->loadByCustomer(Mage::getSingleton('customer/session')->getCustomerId());  

if ($this->getQuoteId() != $customerQuote->getId())
{
$this->_removeAllItems($customerQuote);    //this will remove all items

/*  if ($this->getQuoteId())  // put this on comment, 

it will merge the old carts items with new carts
{
$customerQuote->merge($this->getQuote())
->collectTotals()
->save();
}
$this->setQuoteId($customerQuote->getId());
if ($this->_quote) {
$this->_quote->delete();
}
$this->_quote = $customerQuote;*/
}
return $this;
}
/**
* iterate through quote and remove all items
*
* @return nothing
*/
protected function _removeAllItems($quote)
{

foreach ($quote->getAllItems() as $item)
{
$item->isDeleted(true);
if ($item->getHasChildren()) foreach ($item->getChildren() as $child) $child->isDeleted(true);
}
$quote->collectTotals()->save(); 

this is ready, go for it to crack this
Gaurav Mehta