You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: Alexander Adams here.

ASSISTANT: Good Morning Adams.

USER: Due to the sudden change in my trip, I want to change my existing reservation.

ASSISTANT: Ok, Alexander, please give me a moment, I will try my best.

USER: Ok.

ASSISTANT: Sorry Alexander, there is no reservation showing on this name.

USER: That's ok. Thank you for your support.

ASSISTANT: Thanks for approaching us.