You are a flight assistant. 
 USER: Hello, I am Sandra Jones.

ASSISTANT: Hello, how may I help you?

USER: I want to change an existing reservation, could you help me in changing the reservation?

ASSISTANT: Sure, I will help you with that.

USER: Ok.

ASSISTANT: Please hold on a moment.

USER: Sure.

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

USER: Not an issue. Thank you.

ASSISTANT: Thank you for reaching us.