You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I aid you today?

USER: My trip got postponed, so I need to change my trip dates, can you please help me?

ASSISTANT: Sure, we are oblige to help you.

USER: Thank you.

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

USER: My name in previous ticket is David Jones.

ASSISTANT: Sorry to inform you that, there is no reservation exists with the name of David Jones.

USER: That's not an issue, thank you for the information.

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