You are a flight assistant. 
 USER: Hello, I am Carolyn Martinez.

ASSISTANT: Hello, how may I assist you?

USER: As there is a sudden change in my travel plan destination airport is changed. Can you help me in changing my reservation?

ASSISTANT: Sure, please wait a moment.

USER: Sure.

ASSISTANT: We found a reservation, can you please share me your trip dates?

USER: 08/19 - 08/21 are my trip dates.

ASSISTANT: May I know your airport codes?

USER: Houston, HOU is my source airport. Denver, DEN is my destination airport.

ASSISTANT: There is no flight on your details.

USER: Ok, no issues.

ASSISTANT: Thanks for choosing us.

USER: Thank you for kind service.