You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help 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 am here to help you with that.

USER: Thank you.

ASSISTANT: Please wait for a minute.

USER: Sure, take your time.

ASSISTANT: Sorry to say that, there is no reservation found on your name in our database.

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

ASSISTANT: Thank you for reaching us. May I know your name for the documentation purpose?

USER: My name is Jeffrey Miller.

ASSISTANT: Thank you.