You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. What can I do for you now?

USER: I want to change my existing reservation in the name of Rebecca Hill. Can you help me in this?

ASSISTANT: Ok. Please wait.

USER: Sure.

ASSISTANT: Sorry, there was no reservation found on your name.

USER: It's ok, not an issue.

ASSISTANT: Thank you for choosing us.

USER: Thank you for your information.