You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I guide you?

USER: I am Ryan Garcia, want to alter my recent reservation because I made my booking with wrong travelling dates. Please help me out with that.

ASSISTANT: Sure, I will help you. Please give me a minute to check your existing reservation.

USER: Sure, take your time.

ASSISTANT: Sorry, but there is no reservation found with your name.

USER: It's ok, no issue. Anyway, thank you for your help.

ASSISTANT: You are welcome.