Southwest.com's ticket purchase page allows you to save the address and credit card info when you are buying a ticket, though oddly not when you are re-using ticketless funds. Presumably this sends a cookie to your browser.

The problem I have is that I have one card for business and another for personal travel. Once the cookie has saved one credit card, you can specify "save information" for a purchase with the other card, but the information is never updated. This means that each and every time I have to change the credit card type and expiration date.

Is there a simple way to delete this cookie without deleting all cookies?