You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I assist you?

USER: Can you please help me in changing my reservation?

ASSISTANT: Ok, please can I know your name to check for reservation status?

USER: I am Paul Williams.

ASSISTANT: Ok, thank you for waiting. Your reservation is found, may I know your new airport codes to amend?

USER: My airport codes are from HOU to JFK.

ASSISTANT: Ok, please can I know the dates of your journey to proceed?

USER: I am planning to start on Jan 30 and need to return on Feb 01.

ASSISTANT: Ok, please let me know if you have any specifications.

USER: I need a connecting flight.

ASSISTANT: Ok, please can I know if you need anything else?

USER: No.

ASSISTANT: Ok, please wait a moment.

USER: Ok.

ASSISTANT: Thank you for waiting, there is no flight available to amend the reservation you asked.

USER: Ok, no problem.

ASSISTANT: Sorry for the inconveniences cause to you.

USER: Thank you.

ASSISTANT: Thank you for choosing our agency.