You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Is this flight ticket booking agency?

ASSISTANT: Yes, welcome to our agency. How may I assist you today?

USER: I want to change my previous reservation, because I have some other important works on that day, so can you help me in changing my reservation?

ASSISTANT: Sure, I will help you on that.

USER: Thanks.

ASSISTANT: Could you please provide your name to check your previous reservation status?

USER: Sure, my name is Pamela Anderson.

ASSISTANT: Ok Pamela, please wait a moment to check.

USER: Ok.

ASSISTANT: Sorry to inform you, there is no reservation found under your name in our records.

USER: It's ok, no problem.

ASSISTANT: Would you like to ask us anything else?

USER: Nothing, thank you for your information.

ASSISTANT: Thank you for reaching us, have a great day.