You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you today?

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?

USER: The previous reservation done under the name of Samuel Miller.

ASSISTANT: Sorry, there is no reservation on your name.

USER: Ok, not an problem. Thank you for your information.

ASSISTANT: Thank you.