You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I assist you today?

USER: Can you please help me in changing my recent reservation details? As my planned trip has been postponed.

ASSISTANT: Sure, will you mention your name please?

USER: Sure, my name is Stephen Walker.

ASSISTANT: There is no reservation found under your name.

USER: Oh! May be I have done a wrong booking. Thank you anyways.

ASSISTANT: Welcome, have a great day.