You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you today?

USER: I want to change my existing reservation which is done recently due to some problems, can you please help me in this?

ASSISTANT: Sure, may I know your name to check for the previous reservation?

USER: Ok, my name is Amanda Walker.

ASSISTANT: Amanda, there is no reservation found under your name.

USER: That's fine. Thank you for your appreciable service.

ASSISTANT: Thank you for contacting us.