You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello,.

USER: I am Alexander Wright.

ASSISTANT: How can I help you?

USER: My business trip got postponed, can you please help me in changing my existing reservation?

ASSISTANT: Sure. Wait for a moment.

USER: Ok.

ASSISTANT: Thanks for waiting. There is no reservation found with your name.

USER: Ok, no problem.

ASSISTANT: Thank you for reaching us.

USER: Thanks for your response.