How to send product price alert in magento?

I am using magento 1.4 . Any one please tell me how to send product price alert. Do i need to change any code for that. If i need to change the c开发者_Python百科ode, possible to tell me where exactly to change and what to change?

Price alerts are sent by Mage_ProductAlert_Model_Observer::process() which is called regularly by cron. Any changes you want to make to how alerts are sent will be in there.

If you want to create an alert that will be sent later see Mage_ProductAlert_AddController::priceAction(). It simply creates a Mage_ProductAlert_Model_Price object and saves it with a customer.