You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: I have booked a flight ticket in the last week but now the meeting was postponed. So, I just want to change the travel dates. Can you please help me to do that?

ASSISTANT: Sure, may I know your name please?

USER: Thanks for your response. My name is Robert White.

ASSISTANT: I am sorry no reservation found on your name. That's ok, thank you.

USER: It's ok, not an issue with that. Anyways thank you for your time.