You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: My name is Ronald Allen.

ASSISTANT: Allen, how can I assist you?

USER: My brother has booked a ticket with wrong details. Now, I would like to change my existing reservation. Can you help me?

ASSISTANT: Sure, let me check your reserved ticket status in the database.

USER: Ok, take your time.

ASSISTANT: Allen, please provide your planned dates of travel.

USER: I would like to change my dates of journey to 01/22 and 01/24.

ASSISTANT: May I know your airport codes?

USER: The airport codes remain same, they are JFK and PHX respectively.

ASSISTANT: Please wait for a moment.

USER: Sure. Make sure the price is less than 200.

ASSISTANT: Sorry, no flight is available with your preferences.

USER: That's fine, I will find other way out. Thank you for the information.

ASSISTANT: Thank you for contacting us.