You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I aid you?

USER: Due to some urgent office meeting, I am planning to change my existing reservation. Can you please help me for this?

ASSISTANT: Sure, I can help you. May I know your name?

USER: Myself Ryan Johnson.

ASSISTANT: Please give me a moment to check your ticket status.

USER: Sure.

ASSISTANT: Sorry Ryan Johnson, no reservation is available by your name.

USER: Not a big deal, anyhow thank you very much for your kind information.

ASSISTANT: Thank you for choosing us.