You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Emma Anderson here.

ASSISTANT: How may I assist you Emma Anderson?

USER: Suddenly my friends changed the trip plan.So I want to change my reservation. Can you please help me for that?

ASSISTANT: Wait a moment please.

USER: Ok.

ASSISTANT: Sorry, there is no reservation found with your name.

USER: Ok, thank you for the information.

ASSISTANT: Thank you for contacting us.