You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Donald Turner here.

ASSISTANT: Turner, how can I help you today?

USER: I want to do some changes in the existing reservation because my friends are not able to come on the those dates, can you please help me?

ASSISTANT: Sure, I will help you. Turner, I did not find any reservation with your name. Anything else to change.

USER: Nothing. Thank you for the information.

ASSISTANT: Most welcome, have a good day.