Abstract: A computer system for overlaying content in a designated area of a web page is disclosed. The computer system may be used to run executable code configured to identify a data field in a received web page, insert a visible user control substantially adjacent to the data field, display the web page comprising the user control, and cause a value in the data field to be tracked upon actuation of the user control.

Abstract: A flight-ticket price may be monitored by obtaining an itinerary record associated with a previously-booked flight itinerary, identifying a group of flight segments that corresponds to a ticket, “fingerprinting” the ticket, and determining a schedule to periodically monitor prices associated with the ticket. During at least one price-monitoring period, an up-to-date version of the itinerary record is obtained and “fingerprinted”. The “fingerprints” are used to verify that the flight ticket has not changed significantly, current pricing data is obtained, and a cost saving is determined to be currently obtainable, considering possible change penalties, by re-ticketing or re-booking the group of flight segments.