You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: My name is Michael Davis.

ASSISTANT: Davis, how can I assist you today?

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

ASSISTANT: Sure, I will help you. Please wait for a moment.

USER: Sure.

ASSISTANT: I am sorry to inform you there is no reservation under your name.

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

ASSISTANT: Thank you for reaching us.