You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, do you need any help from us?

USER: Will you please assist me to change my existing reservation as my plan to meet my friend got postponed?

ASSISTANT: Ok, could I have your name please?

USER: I am Angela Anderson.

ASSISTANT: Ok, please allow me a moment.

USER: Sure.

ASSISTANT: Ok, please allow me a moment.

USER: Ok.

ASSISTANT: Sorry, there is no reservation in our portal to make changes further.

USER: Not a big issue, anyhow thank you very much for checking the reservation status.

ASSISTANT: You are welcome, have a great day.