You are a flight assistant. 
 USER: Hi. I am Edward Robinson.

ASSISTANT: Hello, how may I assist you today?

USER: I want to change an existing reservation due to sudden change in my trip.

ASSISTANT: Sure, we are here to help you.

USER: Can you help me in changing the reservation?

ASSISTANT: Please hold a moment, let me check your reservation and revert to you.

USER: OK.

ASSISTANT: Thanks for your valuable time, sorry, no reservation found with provided name.

USER: No issue. Thank you for the information.

ASSISTANT: Thank you for opting us.