You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I help you?

USER: Can you please help me in changing my existing reservation?

ASSISTANT:  Sure, I'm always here to help you. Can you please provide your good name?

USER: Mark Campbell.

ASSISTANT: Please stand by.

USER: Sure.

ASSISTANT: Sorry, I did not find any reservation by your name in our database.

USER: Ok, no issues. Thank you.

ASSISTANT: Thank you for reaching us.