You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you today?

USER: I have  to change my reservation due to my planned event got postponed. So please help me with that.

ASSISTANT: Sure, I will help you.

USER: Thank you.

ASSISTANT: Please help me with your name.

USER: Sure, please check the reservation with my name Donald Martin.

ASSISTANT: Donald Martin, I am really sorry to inform you that there is no booking found on your name.

USER: Oh! It may not be booked properly. Anyway, thank you for your time.

ASSISTANT: Thank you for reaching us. Have a great time.

USER: Most welcome.