You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I serve you now?

USER: I want to change my existing reservation due to sudden change in my family trip dates. Can you help me with that?

ASSISTANT: Sure, I will help you.

USER: Thank you.

ASSISTANT: Please, provide your name. So that I can search an existing reservation with your name.

USER: Sure, Jerry Nelson here.

ASSISTANT: Wait a minute, please.

USER: Sure, I will wait.

ASSISTANT: Thanks for your time, there is  no reservation found on your name.

USER: Ok, no problem.

ASSISTANT: Thank you for availing us.

USER: Thank you for your quick response.