You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you today?

USER: Can you please help me in doing some modifications in my recent reservation? As my planned trip has been postponed to some other dates.

ASSISTANT: Sure, I will help you. Please let me know with your name.

USER: Sure, my name is Richard Green.

ASSISTANT: Please allow me a minute.

USER: Sure, I'll wait for your response.

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

USER: Oh! May be I have done a wrong booking. Thank you anyways.

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