You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Frank Jones.

ASSISTANT: How can I aid you at this moment?

USER: I want to change an existing reservation. Can you please help me in that?

ASSISTANT: Sure, I will help you with that. Please wait a moment, I will check your previous reservation status.

USER: Sure, take your own time.

ASSISTANT: There is no previous reservation available in your name.

USER: No issues. Thank you for your information.

ASSISTANT: Thank you for contacting us, have a good day.