You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I aid you?

USER: I feel like spending some more time with my friends. So, I would like to change my existing reservation. Can you help me?

ASSISTANT: Sure, provide me your name to check your previous reservation?

USER: My name is Emma Phillips.

ASSISTANT: Ok Emma, let me check your reservation in our data base.

USER: Sure.

ASSISTANT: Sorry Emma, no reservation found on your name.

USER: Ok, that's fine. Thank you for the information.

ASSISTANT: Thank you for contacting us.