You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I aid you today?

USER: I am Frank Perez. Please change my existing reservation, with the current journey details.

ASSISTANT: Sure, please wait a while I will check and let you know.

USER: Sure.

ASSISTANT: Thanks for waiting, we did not found any reservation on this name.

USER: Ok.

ASSISTANT: Thanks for choosing us.

USER: Thank you for sharing the information.