You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I aid you?

USER: I want to change my reservation, due to some problems I am unable to travel those dates can you please help me?

ASSISTANT: Sure, let me know your name to proceed?

USER: Sure, my name is Brenda Thompson.

ASSISTANT: Sorry, no reservation found on your name.

USER: Oh! It's ok no problem. Thank you for your information.

ASSISTANT: Thank you for choosing us, have a nice day.