You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I assist you?

USER: Dennis Collins here. Can you please help me in changing my recent reservation?

ASSISTANT: Sure, please wait a moment I will check your reservation details and proceed further.

USER: Sure.

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

USER: That's ok, thank you for your service anyways.

ASSISTANT: Thank you for choosing us, have a nice day.