You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you today?

USER: Daniel Nelson here.

ASSISTANT: Nice to meet you.

USER: Due to sudden change in my planned date of journey, I would like to change my reservation. Can you please help me out with that?

ASSISTANT: Sure, please give me a moment.

USER: Ok, I will wait.

ASSISTANT: Thanks for waiting, there is no reservation found under your name.

USER: Anyway, thanks for the information.

ASSISTANT: Welcome, have a great day.