You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I aid you today?

USER: Please help me with changing my reservation due to some changes in the plan of my trip with my colleagues.

ASSISTANT: Sure, I will help you with that.

USER: Thank you.

ASSISTANT: May I know your name please to proceed further?

USER: My name is Sarah Taylor.

ASSISTANT: I am sorry to inform that  there is no reservation found under your name.

USER: It's ok, thank you for your help.

ASSISTANT: Thank you for contacting us.