You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Myself Debra Hill.

ASSISTANT: How may I aid you?

USER: I want to change my existing reservation, can you help me in that?

ASSISTANT: Sure, I will help you.

USER: Thank you.

ASSISTANT: Sorry, there are no reservation found on your name.

USER: That's ok, no problem. Thank you for the information.

ASSISTANT: Thank you for contacting us.