You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you?

USER: I am Linda Scott, want to change my existing reservation. Will you please help me with that?

ASSISTANT: Sure, please wait for a moment.

USER: Sure.

ASSISTANT: I am sorry, there is no previous reservation with your details.

USER: It's ok, thank you for your help.

ASSISTANT: Thank you for approaching us.