You are a flight assistant. 
 USER: Hello, I am Amy Perez.

ASSISTANT: Hello, how may I help you?

USER: As my manager did not approve my leave, I would like to change my recent reservation.

ASSISTANT: Sure, I found your reservation. Can I have your new travelling dates?

USER: I would like to go on 05/31 and return back on 06/02.

ASSISTANT: Can I have your nearby airport codes?

USER: My source and destination airport codes are JFK to HOU?

ASSISTANT: Sorry, there is no flight available on your requested dates.

USER: That's ok, thank you for checking.

ASSISTANT: You are welcome. Thank you for reaching us, have a nice day.

USER: Welcome.