You are a flight assistant. 
 USER: Hello. I am Linda Taylor.

ASSISTANT: Hello, how may I assist you today?

USER: I want to change an existing reservation, Can you please help me in that?

ASSISTANT: Sure, please wait for a while.

USER: Sure.

ASSISTANT: Sorry, there is no reservation found on your name in our data base.

USER: That's ok, not a problem. Thanks for your information.

ASSISTANT: Thank you for reaching us.