You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I aid you today?

USER: I would like to shift my planned dates to next month, please help me in changing my existing reservation.

ASSISTANT: Firstly, provide me your name to check the previous reservation on your name in our data base.

USER: Sure, my name is Christine Smith.

ASSISTANT: Sorry Christine Smith, there is no active reservation on your name.

USER: Ok, no issue. Thank you for your information.

ASSISTANT: Thank you for reaching us.