You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Myself Rebecca Williams.

ASSISTANT: How may I assist you today?

USER: For some issues I want to change my recent reservation, can you please help me with it?

ASSISTANT: Sure, I will help you with that, please wait for a minute.

USER: Ok, take your time.

ASSISTANT: We cannot find any reservation with your name in our database.

USER: That's ok, thank you for checking.

ASSISTANT: It's my pleasure.