You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. In which way I can help you at this moment?

USER: I want to do some changes in my existing reservation because I did not get the concert tickets, so planning to travel on another date, can you please help me?

ASSISTANT: Sure, I will help you with changing the reservation.

USER: Thank you.

ASSISTANT: Please give me a moment to check existing reservation whether it is existing or not.

USER: Sure, take your time.

ASSISTANT: Please provide me your good name for checking.

USER: My name is Michelle Allen.

ASSISTANT: Sorry Allen, I did not came across your name in the reservation list. Thank you for choosing us.

USER: Ok, no problem. Thank you for checking.

ASSISTANT: Most welcome. Have a great day.