You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I help you?

USER: As my friends has changed our trip dates, I want your help to change my recent reservation. Can you please help me with that?

ASSISTANT: Ok, let me know your name for checking?

USER: Sure, please search for the reservation with the name of Donald Thompson.

ASSISTANT: Give me a moment to check please.

USER: Sure.

ASSISTANT: Donald Thompson, no reservation found by your name. Sorry.

USER: That's ok, may be I have done a wrong booking. Thank you anyways.

ASSISTANT: Thank you for reaching our services, have a nice day.