I am trying to implement something new, I guess. I want to use magento as shopping cart for my new site where I WANT TO SEND few custom fields that will be filled during checkout process TO EXTERNAL application, that may or may not reside on same server, ONLY IF PAYMENT IS SUCCESSFUL. These custom fields upon succesfull transaction need to be sent through post method. I hope I am clear on this. Please guide me on this, how I can achieve this.