You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I aid you today?

USER: I want to change my reservation as my trip is postponed, can you please help me?

ASSISTANT: Sure, I will help you.

USER: Thank you.

ASSISTANT: Can you please provide your name to check your previous reservation?

USER: My name is Gregory Perez.

ASSISTANT: Ok, please be on hold.

USER: Sure.

ASSISTANT: Sorry to inform you that, there is no reservation found with your name in our records.

USER: No problem, thank you for checking.

ASSISTANT: Thank you for reaching us, have a great day.