You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, what can I guide you at this moment?

USER: I have planned a trip but suddenly one of my sister blessed with a baby, so I want to change the trip to other dates, can you please help in modifying that one?

ASSISTANT: Sure, I will assist you about that. Can you please help me with your name to check the existing reservation under your name?

USER: Thank you for helping in that one, my name is Kevin Parker.

ASSISTANT: Sorry there is no existing reservations under your name to change Parker.

USER: Ok, I think it is not yet confirmed till now, I will look after some time, thank you for your help.

ASSISTANT: Yes, it might be the problem. It's my duty, thank you for opting our service. Hope you have a nice day.

USER: Most welcome.