You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Raymond Allen.

ASSISTANT: How can I amend you today?

USER: I want to change my dates of reservation as some more friends want to join with us if I change the dates.

ASSISTANT: Ok.

USER: So, can you help me with changing the dates of my reservation?

ASSISTANT: Sure, I am here to aid you. Please wait for a while, I will let you know.

USER: Ok.

ASSISTANT: Thanks for being patient, unfortunately no reservation is done previously to proceed further.

USER: Fine, thanks for the information.

ASSISTANT: Thank you for opting us, Have a great day.