You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. May I know your name?

USER: I am Alexander Rodriguez.

ASSISTANT: How can I assist you?

USER: Due to some emergency work, I need  your help in changing my existing reservation.

ASSISTANT: Ok, Please stand by.

USER: Ok.

ASSISTANT: Thanks for being patience. There is no reservation found with your name.

USER: Ok, thanks for the information.

ASSISTANT: Thanks for choosing us.