You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I help you?

USER: I need your help in changing my existing reservation due to sudden change in my trip dates.

ASSISTANT: Sure. May I know your good name?

USER: I am Michael Hernandez.

ASSISTANT: Please, wait.

USER: Sure.

ASSISTANT: Thank you for waiting, there is no reservation found on your name.

USER: Ok, not an issue. Thank you.

ASSISTANT: Thank you for choosing us.