You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: I'm Dennis Hernandez, can you help me in changing the reservation?

ASSISTANT: Sure, please wait for a while.

USER: Sure.

ASSISTANT: Sorry, there is no reservation found with your name in my records.

USER: That's fine, thank you for the information.

ASSISTANT: Most welcome.