You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I aid you for today?

USER: I have to change my ticket reservation that there is a some issue happen in our group during the trip, so please change the dates of the trip.

ASSISTANT: Yes, I will help you about that. Can you please provide your name to check the reservation status under your name?

USER: My name is John Anderson.

ASSISTANT: Sorry Anderson, there is no reservation under your name in our listings.

USER: Ok, that's fine, not a problem with that one, I can book a ticket again with my dates, thank you for your information.

ASSISTANT: My pleasure, thank you for reaching out here.