You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I serve you at this moment?

USER: I want to change my existing reservation, can you help me for this one?

ASSISTANT: Sure, may I know your name?

USER: Sure,Linda Mitchell here.

ASSISTANT: Ok, please wait for a minute.

USER: Sure.

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

USER: No issues, thank you for the information.

ASSISTANT: Thank you for reaching us.