You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, what sort of help are you seeking from me?

USER: As I have planned a holiday trip with my friends on 08/05 but, suddenly I need to attend a client meeting in head quarters at Denver. so I need to change my reservation. Can you please help me in changing my reservation?

ASSISTANT: Sure, I am ready to help you.

USER: Thank you for considering my request.

ASSISTANT: To change the reservation, can you please provide on what name reservation has been made?

USER: Sure, reservation has been made with the name of Christopher Thomas.

ASSISTANT: Ok, please give me a minute to check the reservation in the list and revert to you within a minute.

USER: Ok, I will wait.

ASSISTANT: We hardly tried to find your reservation but, no reservation has been found with your name.

USER: Ok, no problem. May I did not reserve it properly.

ASSISTANT: Ok.

USER: Thank you for your quick response.

ASSISTANT: Thank you for availing us.