You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you?

USER: Timothy Anderson here. Due to some personal issue I want to change my recent reservation with new trip, can you help me to change the reservation?

ASSISTANT: Sure, please wait a moment.

USER: Ok, take your own time.

ASSISTANT: There is no reservation on your name.

USER: That's fine, thanks for your valuable information.

ASSISTANT: Thank you so much.