You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: Ruth Clark here.

ASSISTANT: How may I assist you Ruth Clark?

USER: Can you help me in changing my reservation to next weekend? Please check.

ASSISTANT: Sure, wait for a while please.

USER: Sure.

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

USER: That's fine.

ASSISTANT: Thank you for reaching us.

USER: Anyway, thank you for your search.