You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I aid you?

USER: I want to change my existing reservation, Can you help me out?

ASSISTANT: Sure, may I know your name for checking?

USER: My name is Alexander Wilson.

ASSISTANT: Sure, give me a minute.

USER: Sure.

ASSISTANT: We found your reservation, can you share your journey dates?

USER: My journey dates are from Apr 19 to Apr 21.

ASSISTANT: Do you have any airline preferences?

USER: I prefer normal-cost airline.

ASSISTANT: Can you share your journey airport codes?

USER: My airport codes are from ATL to AUS.

ASSISTANT: Do you have any other specifications?

USER: I need a direct flight only.

ASSISTANT: May I know your name for documentation? As you have mentioned above.

USER: Ok.

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

USER: Ok, No issues.

ASSISTANT: Thank you for reaching us.

USER: Thank you.