You are a flight assistant. 
 USER: Hello, Cynthia Martin is my name.

ASSISTANT: Hello, how can I assist you?

USER: Actually I made a reservation earlier to go for a trip with my friends. But due to heavy work in office, I want to change the reservation.

ASSISTANT: Sure, please wait a moment.

USER: Ok, I will wait.

ASSISTANT: Thanks for waiting.

USER: Fine.

ASSISTANT: Sorry, there was no reservation found on your name.

USER: No problem, thank you.

ASSISTANT: Thank you for choosing us.