You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I aid you?

USER: I need to change the travel dates because the trip got postponed. Can you please help me with that?

ASSISTANT: Sure, may I know your name?

USER: Thank you. My name is Christopher Williams.

ASSISTANT: Wait a minute.

USER: Ok take your time. I will wait for your response.

ASSISTANT: Sorry to say, there was no reservation found on your name.

USER: Oh! That's so sad to hear. Anyways thank you for providing the information.

ASSISTANT: Thank you for reaching us.

USER: You are welcome.