You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you at this minute?

USER: Can you please help me in changing my reservation which I have done in last week?

ASSISTANT: Ok, I will help you with that. Can I know your name?

USER: Yes, my name is Pamela Walker.

ASSISTANT: Ok, Pamela Walker, please wait for a minute.

USER: Sure, I'll be online.

ASSISTANT: I could not found any reservation with your name in our database.

USER: Oh! That's ok, thank you for giving the information.

ASSISTANT: Thank you for approaching us.